此操作实测是可以的，完美解决

Nextcloud/ownCloud在URL中默认是显示入口文件index.php的：

去除URL中的入口文件有这样3点好处：

启用Rewrite

在Ubuntu/Debian中:

a2enmod rewrite #激活mod_rewrite

service apache2 restart #重启apache

在CentOS/RedHat中，需要手动在虚拟主机配置文件中添加以下内容：

LoadModule rewrite_module modules/mod_rewrite.so

然后重启Apache

service apache2 restart

方法1：config.php+OCC命令

编辑config/config.php

在config.php中设置规则，只需加入以下2行：

'overwrite.cli.url' => 'ownCloud/Nextcloud访问地址',
'htaccess.RewriteBase' => '/',

第一行一般已经存在，可以不再添加，如果和你当前的Nextcloud/ownCloud的访问地址不同，则要修改为当前地址。

以下是一个config.php示例的部分内容，需要添加或修改的两行已用黄色标出

  'overwrite.cli.url' => 'http://192.168.3.3', 
  'dbtype' => 'mysql',
  'version' => '12.0.0.16',
  'dbname' => 'nc',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'dbuser' => 'user',
  'dbpassword' => 'password',
  'installed' => true,
  'htaccess.RewriteBase' => '/',

现在可以将它保存了。

使用OCC命令生成.htaccess文件

别急着访问Nextcloud，我们只是添加了生成.htaccess的规则而已。现在要使用OCC命令重新生成.htaccess

OCC命令用法：【ownCloud】之终极管理：OCC命令行工具、ownCloud/Nextcloud OCC命令行工具详解（1）

使用以下命令生成.htaccess文件：

Ubuntu/Debian类系统

sudo -u www-data php occ maintenance:update:htaccess

CentOS/RedHat：

sudo -u apache php occ maintenance:update:htaccess

如图：

访问你的Nextcloud，index.php已经消失了。

方法2：手动添加规则

打开Nextcloud/ownCloud根目录下的.htaccess文件，在文件最后插入以下内容：

ErrorDocument 403 /core/templates/403.php
ErrorDocument 404 /core/templates/404.php
<IfModule mod_rewrite.c>
  Options -MultiViews
  RewriteRule ^core/js/oc.js$ index.php [PT,E=PATH_INFO:$1]
  RewriteRule ^core/preview.png$ index.php [PT,E=PATH_INFO:$1]
  RewriteCond %{REQUEST_FILENAME} !\.(css|js|svg|gif|png|html|ttf|woff|ico|jpg|jpeg)$
  RewriteCond %{REQUEST_FILENAME} !core/img/favicon.ico$
  RewriteCond %{REQUEST_FILENAME} !/remote.php
  RewriteCond %{REQUEST_FILENAME} !/public.php
  RewriteCond %{REQUEST_FILENAME} !/cron.php
  RewriteCond %{REQUEST_FILENAME} !/core/ajax/update.php
  RewriteCond %{REQUEST_FILENAME} !/status.php
  RewriteCond %{REQUEST_FILENAME} !/ocs/v1.php
  RewriteCond %{REQUEST_FILENAME} !/ocs/v2.php
  RewriteCond %{REQUEST_FILENAME} !/robots.txt
  RewriteCond %{REQUEST_FILENAME} !/updater/
  RewriteCond %{REQUEST_FILENAME} !/ocs-provider/
  RewriteCond %{REQUEST_URI} !^/.well-known/acme-challenge/.*
  RewriteRule . index.php [PT,E=PATH_INFO:$1]
  RewriteBase /
  <IfModule mod_env.c>
    SetEnv front_controller_active true
    <IfModule mod_dir.c>
      DirectorySlash off
    </IfModule>
  </IfModule>
</IfModule>

保存退出，重新访问Nextcloud，效果与使用OCC命令一样。

一个完整的.htaccess文件：

<IfModule mod_headers.c>
  <IfModule mod_setenvif.c>
    <IfModule mod_fcgid.c>
       SetEnvIfNoCase ^Authorization$ "(.+)" XAUTHORIZATION=$1
       RequestHeader set XAuthorization %{XAUTHORIZATION}e env=XAUTHORIZATION
    </IfModule>
    <IfModule mod_proxy_fcgi.c>
       SetEnvIfNoCase Authorization "(.+)" HTTP_AUTHORIZATION=$1
    </IfModule>
  </IfModule>

  <IfModule mod_env.c>
    # Add security and privacy related headers
    Header set X-Content-Type-Options "nosniff"
    Header set X-XSS-Protection "1; mode=block"
    Header set X-Robots-Tag "none"
    Header set X-Download-Options "noopen"
    Header set X-Permitted-Cross-Domain-Policies "none"
    SetEnv modHeadersAvailable true
  </IfModule>

  # Add cache control for static resources
  <FilesMatch "\.(css|js|svg|gif)$">
    Header set Cache-Control "max-age=15778463"
  </FilesMatch>
  
  # Let browsers cache WOFF files for a week
  <FilesMatch "\.woff$">
    Header set Cache-Control "max-age=604800"
  </FilesMatch>
</IfModule>
<IfModule mod_php5.c>
  php_value upload_max_filesize 511M
  php_value post_max_size 511M
  php_value memory_limit 512M
  php_value mbstring.func_overload 0
  php_value always_populate_raw_post_data -1
  php_value default_charset 'UTF-8'
  php_value output_buffering 0
  <IfModule mod_env.c>
    SetEnv htaccessWorking true
  </IfModule>
</IfModule>
<IfModule mod_php7.c>
  php_value upload_max_filesize 511M
  php_value post_max_size 511M
  php_value memory_limit 512M
  php_value mbstring.func_overload 0
  php_value default_charset 'UTF-8'
  php_value output_buffering 0
  <IfModule mod_env.c>
    SetEnv htaccessWorking true
  </IfModule>
</IfModule>
<IfModule mod_rewrite.c>
  RewriteEngine on
  RewriteCond %{HTTP_USER_AGENT}  DavClnt
  RewriteRule ^$         /remote.php/webdav/          [L,R=302]
  RewriteRule .* - [env=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
  RewriteRule ^\.well-known/host-meta /public.php?service=host-meta [QSA,L]
  RewriteRule ^\.well-known/host-meta\.json /public.php?service=host-meta-json [QSA,L]
  RewriteRule ^\.well-known/carddav /remote.php/dav/ [R=301,L]
  RewriteRule ^\.well-known/caldav /remote.php/dav/ [R=301,L]
  RewriteRule ^remote/(.*) remote.php [QSA,L]
  RewriteRule ^(?:build|tests|config|lib|3rdparty|templates)/.* - [R=404,L]
  RewriteCond %{REQUEST_URI} !^/.well-known/acme-challenge/.*
  RewriteRule ^(?:\.|autotest|occ|issue|indie|db_|console).* - [R=404,L]
</IfModule>
<IfModule mod_mime.c>
  AddType image/svg+xml svg svgz
  AddEncoding gzip svgz
</IfModule>
<IfModule mod_dir.c>
  DirectoryIndex index.php index.html
</IfModule>
AddDefaultCharset utf-8
Options -Indexes
<IfModule pagespeed_module>
  ModPagespeed Off
</IfModule>
#### DO NOT CHANGE ANYTHING ABOVE THIS LINE ####

ErrorDocument 403 /core/templates/403.php
ErrorDocument 404 /core/templates/404.php
<IfModule mod_rewrite.c>
  Options -MultiViews
  RewriteRule ^core/js/oc.js$ index.php [PT,E=PATH_INFO:$1]
  RewriteRule ^core/preview.png$ index.php [PT,E=PATH_INFO:$1]
  RewriteCond %{REQUEST_FILENAME} !\.(css|js|svg|gif|png|html|ttf|woff|ico|jpg|jpeg)$
  RewriteCond %{REQUEST_FILENAME} !core/img/favicon.ico$
  RewriteCond %{REQUEST_FILENAME} !/remote.php
  RewriteCond %{REQUEST_FILENAME} !/public.php
  RewriteCond %{REQUEST_FILENAME} !/cron.php
  RewriteCond %{REQUEST_FILENAME} !/core/ajax/update.php
  RewriteCond %{REQUEST_FILENAME} !/status.php
  RewriteCond %{REQUEST_FILENAME} !/ocs/v1.php
  RewriteCond %{REQUEST_FILENAME} !/ocs/v2.php
  RewriteCond %{REQUEST_FILENAME} !/robots.txt
  RewriteCond %{REQUEST_FILENAME} !/updater/
  RewriteCond %{REQUEST_FILENAME} !/ocs-provider/
  RewriteCond %{REQUEST_URI} !^/.well-known/acme-challenge/.*
  RewriteRule . index.php [PT,E=PATH_INFO:$1]
  RewriteBase /
  <IfModule mod_env.c>
    SetEnv front_controller_active true
    <IfModule mod_dir.c>
      DirectorySlash off
    </IfModule>
  </IfModule>
</IfModule>

附：NGINX的配置

NGINX和Apache的配置文件不同，所以在NGINX中，上面所述两种方法都是无效的。

NGINX的示例文件

以下是两种NGINX的配置示例，均来自官方文档。

当Nextcloud/ownCloud被安装于根目录时：

upstream php-handler {
    server 127.0.0.1:9000;
    #server unix:/var/run/php5-fpm.sock;
}

server {
    listen 80;
    server_name cloud.example.com;
    # enforce https
    return 301 https://$server_name$request_uri;
}

server {
    listen 443 ssl;
    server_name cloud.example.com;

    ssl_certificate /etc/ssl/nginx/cloud.example.com.crt;
    ssl_certificate_key /etc/ssl/nginx/cloud.example.com.key;

    # Add headers to serve security related headers
    # Before enabling Strict-Transport-Security headers please read into this
    # topic first.
    # add_header Strict-Transport-Security "max-age=15768000;
    # includeSubDomains; preload;";
    #
    # WARNING: Only add the preload option once you read about
    # the consequences in https://hstspreload.org/. This option
    # will add the domain to a hardcoded list that is shipped
    # in all major browsers and getting removed from this list
    # could take several months.
    add_header X-Content-Type-Options nosniff;
    add_header X-Frame-Options "SAMEORIGIN";
    add_header X-XSS-Protection "1; mode=block";
    add_header X-Robots-Tag none;
    add_header X-Download-Options noopen;
    add_header X-Permitted-Cross-Domain-Policies none;

    # Path to the root of your installation
    root /var/www/nextcloud/;

    location = /robots.txt {
        allow all;
        log_not_found off;
        access_log off;
    }

    # The following 2 rules are only needed for the user_webfinger app.
    # Uncomment it if you're planning to use this app.
    #rewrite ^/.well-known/host-meta /public.php?service=host-meta last;
    #rewrite ^/.well-known/host-meta.json /public.php?service=host-meta-json
    # last;

    location = /.well-known/carddav {
      return 301 $scheme://$host/remote.php/dav;
    }
    location = /.well-known/caldav {
      return 301 $scheme://$host/remote.php/dav;
    }

    # set max upload size
    client_max_body_size 512M;
    fastcgi_buffers 64 4K;

    # Disable gzip to avoid the removal of the ETag header
    gzip off;

    # Uncomment if your server is build with the ngx_pagespeed module
    # This module is currently not supported.
    #pagespeed off;

    error_page 403 /core/templates/403.php;
    error_page 404 /core/templates/404.php;

    location / {
        rewrite ^ /index.php$uri;
    }

    location ~ ^/(?:build|tests|config|lib|3rdparty|templates|data)/ {
        deny all;
    }
    location ~ ^/(?:\.|autotest|occ|issue|indie|db_|console) {
        deny all;
    }

    location ~ ^/(?:index|remote|public|cron|core/ajax/update|status|ocs/v[12]|updater/.+|ocs-provider/.+|core/templates/40[34])\.php(?:$|/) {
        fastcgi_split_path_info ^(.+\.php)(/.*)$;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
        fastcgi_param HTTPS on;
        #Avoid sending the security headers twice
        fastcgi_param modHeadersAvailable true;
        fastcgi_param front_controller_active true;
        fastcgi_pass php-handler;
        fastcgi_intercept_errors on;
        fastcgi_request_buffering off;
    }

    location ~ ^/(?:updater|ocs-provider)(?:$|/) {
        try_files $uri/ =404;
        index index.php;
    }

    # Adding the cache control header for js and css files
    # Make sure it is BELOW the PHP block
    location ~* \.(?:css|js)$ {
        try_files $uri /index.php$uri$is_args$args;
        add_header Cache-Control "public, max-age=7200";
        # Add headers to serve security related headers (It is intended to
        # have those duplicated to the ones above)
        # Before enabling Strict-Transport-Security headers please read into
        # this topic first.
        # add_header Strict-Transport-Security "max-age=15768000;
        #  includeSubDomains; preload;";
        #
        # WARNING: Only add the preload option once you read about
        # the consequences in https://hstspreload.org/. This option
        # will add the domain to a hardcoded list that is shipped
        # in all major browsers and getting removed from this list
        # could take several months.
        add_header X-Content-Type-Options nosniff;
        add_header X-Frame-Options "SAMEORIGIN";
        add_header X-XSS-Protection "1; mode=block";
        add_header X-Robots-Tag none;
        add_header X-Download-Options noopen;
        add_header X-Permitted-Cross-Domain-Policies none;
        # Optional: Don't log access to assets
        access_log off;
    }

    location ~* \.(?:svg|gif|png|html|ttf|woff|ico|jpg|jpeg)$ {
        try_files $uri /index.php$uri$is_args$args;
        # Optional: Don't log access to other assets
        access_log off;
    }
}

当Nextcloud/ownCloud被安装于子目录时：

upstream php-handler {
    server 127.0.0.1:9000;
    #server unix:/var/run/php5-fpm.sock;
}

server {
    listen 80;
    server_name cloud.example.com;
    # enforce https
    return 301 https://$server_name$request_uri;
}

server {
    listen 443 ssl;
    server_name cloud.example.com;

    ssl_certificate /etc/ssl/nginx/cloud.example.com.crt;
    ssl_certificate_key /etc/ssl/nginx/cloud.example.com.key;

    # Add headers to serve security related headers
    # Before enabling Strict-Transport-Security headers please read into this
    # topic first.
    #add_header Strict-Transport-Security "max-age=15768000;
    # includeSubDomains; preload;";
    add_header X-Content-Type-Options nosniff;
    add_header X-Frame-Options "SAMEORIGIN";
    add_header X-XSS-Protection "1; mode=block";
    add_header X-Robots-Tag none;
    add_header X-Download-Options noopen;
    add_header X-Permitted-Cross-Domain-Policies none;

    # Path to the root of your installation
    root /var/www/;

    location = /robots.txt {
        allow all;
        log_not_found off;
        access_log off;
    }

    # The following 2 rules are only needed for the user_webfinger app.
    # Uncomment it if you're planning to use this app.
    # rewrite ^/.well-known/host-meta /nextcloud/public.php?service=host-meta
    # last;
    #rewrite ^/.well-known/host-meta.json
    # /nextcloud/public.php?service=host-meta-json last;

    location = /.well-known/carddav {
      return 301 $scheme://$host/nextcloud/remote.php/dav;
    }
    location = /.well-known/caldav {
      return 301 $scheme://$host/nextcloud/remote.php/dav;
    }

    location /.well-known/acme-challenge { }

    location ^~ /nextcloud {

        # set max upload size
        client_max_body_size 512M;
        fastcgi_buffers 64 4K;

        # Disable gzip to avoid the removal of the ETag header
        gzip off;

        # Uncomment if your server is build with the ngx_pagespeed module
        # This module is currently not supported.
        #pagespeed off;

        error_page 403 /nextcloud/core/templates/403.php;
        error_page 404 /nextcloud/core/templates/404.php;

        location /nextcloud {
            rewrite ^ /nextcloud/index.php$uri;
        }

        location ~ ^/nextcloud/(?:build|tests|config|lib|3rdparty|templates|data)/ {
            deny all;
        }
        location ~ ^/nextcloud/(?:\.|autotest|occ|issue|indie|db_|console) {
            deny all;
        }

        location ~ ^/nextcloud/(?:index|remote|public|cron|core/ajax/update|status|ocs/v[12]|updater/.+|ocs-provider/.+|core/templates/40[34])\.php(?:$|/) {
            fastcgi_split_path_info ^(.+\.php)(/.*)$;
            include fastcgi_params;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            fastcgi_param PATH_INFO $fastcgi_path_info;
            fastcgi_param HTTPS on;
            #Avoid sending the security headers twice
            fastcgi_param modHeadersAvailable true;
            fastcgi_param front_controller_active true;
            fastcgi_pass php-handler;
            fastcgi_intercept_errors on;
            fastcgi_request_buffering off;
        }

        location ~ ^/nextcloud/(?:updater|ocs-provider)(?:$|/) {
            try_files $uri/ =404;
            index index.php;
        }

        # Adding the cache control header for js and css files
        # Make sure it is BELOW the PHP block
        location ~* \.(?:css|js)$ {
            try_files $uri /nextcloud/index.php$uri$is_args$args;
            add_header Cache-Control "public, max-age=7200";
            # Add headers to serve security related headers  (It is intended
            # to have those duplicated to the ones above)
            # Before enabling Strict-Transport-Security headers please read
            # into this topic first.
            # add_header Strict-Transport-Security "max-age=15768000;
            # includeSubDomains; preload;";
            add_header X-Content-Type-Options nosniff;
            add_header X-Frame-Options "SAMEORIGIN";
            add_header X-XSS-Protection "1; mode=block";
            add_header X-Robots-Tag none;
            add_header X-Download-Options noopen;
            add_header X-Permitted-Cross-Domain-Policies none;
            # Optional: Don't log access to assets
            access_log off;
        }

        location ~* \.(?:svg|gif|png|html|ttf|woff|ico|jpg|jpeg)$ {
            try_files $uri /nextcloud/index.php$uri$is_args$args;
            # Optional: Don't log access to other assets
            access_log off;
        }
    }
}

OCP\HintException: [0]: Memcache \OC\Memcache\APCu not available for local cache (Is the matching PHP module installed and enabled?)

其实已经安装 APCu 但是无法正常开启加载。

在，CLI 启用 APCu

/etc/php/7.4/mods-available/apcu.ini

添加，

apc.enable_cli=1

即可解决。

其实这个nextcloud程序视频缩略图有点麻烦，高了几天，也没搞明白，最终问题在哪里，应该是环境配置权限问题， 用宝塔和其他几个主流的LINUX面板套件，装了几次，系统也换了几次，程序能正常安装使用，就是视频缩略图不行，不知道是不是环境权限问题，能想到的，都给了， php-imagick 也安装，ffmpeg 也已经装了， 用 Preview generator 查件查看能正常生成视频缩略图，但是网页端就是加载，显示不了。

官方论坛资官料也找了，

config/config.php added

‘preview_libreoffice_path’ => ‘/etc/libreoffice’,
‘enable_previews’ => true,
‘enabledPreviewProviders’ =>
array (
0 => ‘OC\Preview\TXT’,
1 => ‘OC\Preview\MarkDown’,
2 => ‘OC\Preview\OpenDocument’,
3 => ‘OC\Preview\PDF’,
4 => ‘OC\Preview\MSOffice2003’,
5 => ‘OC\Preview\MSOfficeDoc’,
6 => ‘OC\Preview\PDF’,
7 => ‘OC\Preview\Image’,
8 => ‘OC\Preview\Photoshop’,
9 => ‘OC\Preview\TIFF’,
10 => ‘OC\Preview\SVG’,
11 => ‘OC\Preview\Font’,
12 => ‘OC\Preview\MP3’,
13 => ‘OC\Preview\Movie’,
14 => ‘OC\Preview\MKV’,
15 => ‘OC\Preview\MP4’,
16 => ‘OC\Preview\AVI’,
),

这里也添加了，PSD PDF 都能正常生成。

PHP-FPM env[PATH] 也已经添加

env[PATH] = /usr/local/bin:/usr/bin:/bin:/usr/local/PHP/bin:/usr/lib:/usr

WEB用户权限查了，也都没问题

sudo -u www /bin/sh
sh-5.1$ id
用户id=1001(www) 组id=1001(www) 组=1001(www)
sh-5.1$ type ffmpeg
ffmpeg 是 /usr/bin/ffmpeg
sh-5.1$ ffmpeg -version
ffmpeg version 4.3.4-0+deb11u1 Copyright (c) 2000-2021 the FFmpeg developers
built with gcc 10 (Debian 10.2.1-6)
configuration: –prefix=/usr –extra-version=0+deb11u1 –toolchain=hardened –libdir=/usr/lib/x86_64-linux-gnu –incdir=/usr/include/x86_64-linux-gnu

后来试了 官方的VM虚拟机的系统包，能正常生成缩略图，不是程序问题，也不是后面的配置问题，是宝塔，和其他LINUX面板的WEB环境套件的问题，具体哪里存在问题就不知道了。

用官方的VM虚拟机的套件，执行下面之后，然后，config.php 添加previews后，即可正常。

安装扩展：
sudo apt update
sudo apt-get install imagemagick-common
sudo apt-get install php-imagick
sudo apt-get install ffmpeg

还有阿里云里的配套的带NEXTCLOUD套件的系统，也按上面的操作即可。

折腾好几天，太郁闷了。