/etc/nginx/sites-available/nextcloud我在nginx服务器上运行此扩展中使用的代码时遇到ssl错误
当我用chatGpt搜索这个错误并在我的代码博客上尝试结果时，我无法解决这个错误。我使用的服务器是Ubuntu 20。

upstream php-handler {
    server unix:/var/run/php/php7.4-fpm.sock;
    server 127.0.0.1:9000;
}

server {
    listen 80;
    listen [::]:80;
    server_name cloud.apipool.dev;

    return 301 https://$server_name$request_uri;
}

server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name cloud.apipool.dev;

    root /var/www;

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

    location ^~ /.well-known {
        location = /.well-known/carddav { return 301 /nextcloud/remote.php/dav/; }
        location = /.well-known/caldav  { return 301 /nextcloud/remote.php/dav/; }

        location /.well-known/acme-challenge    { try_files $uri $uri/ =404; }
        location /.well-known/pki-validation    { try_files $uri $uri/ =404; }

        return 301 /nextcloud/index.php$request_uri;
    }

    location ^~ /nextcloud {
        client_max_body_size 512M;
        fastcgi_buffers 64 4K;

        gzip on;
        gzip_vary on;
        gzip_comp_level 4;
        gzip_min_length 256;
        gzip_proxied expired no-cache no-store private no_last_modified no_etag auth;
        gzip_types application/atom+xml application/javascript application/json application/ld+json application/manifest+json application/rss+xml application/vnd.geo+json application/vnd.ms-fontobject application/x-font-ttf application/x-web-app-manifest+json application/xhtml+xml application/xml font/opentype image/bmp image/svg+xml image/x-icon text/cache-manifest text/css text/plain text/vcard text/vnd.rim.location.xloc text/vtt text/x-component text/x-cross-domain-policy;

        add_header Referrer-Policy                      "no-referrer"   always;
        add_header X-Content-Type-Options               "nosniff"       always;
        add_header X-Download-Options                   "noopen"        always;
        add_header X-Frame-Options                      "SAMEORIGIN"    always;
        add_header X-Permitted-Cross-Domain-Policies    "none"          always;
        add_header X-Robots-Tag                         "none"          always;
        add_header X-XSS-Protection                     "1; mode=block" always;

        fastcgi_hide_header X-Powered-By;

        index index.php index.html /nextcloud/index.php$request_uri;

        location = /nextcloud {
            if ( $http_user_agent ~ ^DavClnt ) {
                return 302 /nextcloud/remote.php/webdav/$is_args$args;
            }
        }

        location ~ ^/nextcloud/(?:build|tests|config|lib|3rdparty|templates|data)(?:$|/)    { return 404; }
        location ~ ^/nextcloud/(?:\.|autotest|occ|issue|indie|db_|console)                  { return 404; }

        location ~ \.php(?:$|/) {
            fastcgi_split_path_info ^(.+?\.php)(/.*)$;
            set $path_info $fastcgi_path_info;

            try_files $fastcgi_script_name =404;

            include fastcgi_params;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            fastcgi_param PATH_INFO $path_info;
            fastcgi_param HTTPS on;

            fastcgi_param modHeadersAvailable true;
            fastcgi_param front_controller_active true;
            fastcgi_pass php-handler;

            fastcgi_intercept_errors on;
            fastcgi_request_buffering off;
        }

        location ~ \.(?:css|js|svg|gif)$ {
            try_files $uri /nextcloud/index.php$request_uri;
            expires 6M;
            access_log off;
        }

        location ~ \.woff2?$ {
            try_files $uri /nextcloud/index.php$request_uri;
            expires 7d;
            access_log off;
        }

        location /nextcloud/remote {
            return 301 /nextcloud/remote.php$request_uri;
        }

        location /nextcloud {
            try_files $uri $uri/ /nextcloud/index.php$request_uri;
        }
    }
}

这是我使用的博客代码

nginx: [emerg] no "ssl_certificate" is defined for the "listen ... ssl" directive in /etc/nginx/sites-enabled/nextcloud:14
nginx: configuration file /etc/nginx/nginx.conf test failed

我在做nginx -t的时候得到这个错误消息