nginxconfig.io: Let's Encrypt certbot instructions causes an NGiNX error

Details

Description

When using the instructions provided in nginxconfig.io the resulting website configuration causes NGiNX to error out.

Steps to reproduce

Setup a reverse proxy frontend website, set it to create a new certificate and run the instructions listed.

Screenshots

https://imgur.com/a/zQXXnWF

Expected behavior

Certbot should obtain the cert just fine

Error Message

nginx: [emerg] no "ssl_certificate" is defined for the "listen ... ssl" directive in /etc/nginx/conf.d/nextcloud.domain.com.conf:1
nginx: configuration file /etc/nginx/nginx.conf test failed

OS Version

Ubuntu 20.04 (all updates installed)

NGiNX Version

1.18 (NGiNX repo)

Website configuration

server {
    listen                  443;# ssl http2;
    listen                  [::]:443;# ssl http2;
    server_name             nextcloud.domain.com;
    root                    /var/www/nextcloud.domain.com;

    # SSL
    #;#ssl_certificate         /etc/letsencrypt/live/nextcloud.domain.com/fullchain.pem;
    #;#ssl_certificate_key     /etc/letsencrypt/live/nextcloud.domain.com/privkey.pem;
    #;#ssl_trusted_certificate /etc/letsencrypt/live/nextcloud.domain.com/chain.pem;

    # security
    include                 nginxconfig.io/security.conf;

    # logging
    access_log              /var/log/nginx/nextcloud.domain.com.access.log;
    error_log               /var/log/nginx/nextcloud.domain.com.error.log warn;

    # index.php fallback
    location ~ ^/api/ {
        try_files $uri $uri/ /index.php?$query_string;
    }

    # reverse proxy
    location / {
        proxy_pass http://192.168.7.204;
        include    nginxconfig.io/proxy.conf;
    }

}

# HTTP redirect
server {
    listen      80;
    listen      [::]:80;
    server_name nextcloud.domain.com;
    include     nginxconfig.io/letsencrypt.conf;

    location / {
        return 301 https://nextcloud.domain.com$request_uri;
    }
}