default.conf

        # this file is located in /etc/nginx/conf.d/ directory

        server {
            listen 80 default_server;
            listen [::]:80 default_server;

            server_name YourDNSServer;

            root /var/www/html;

            autoindex off;

            index pihole/index.php index.php index.html index.htm;

            location / {
                expires max;
                try_files $uri $uri/ =404;
            }

            location ~ \.php$ {
                include fastcgi_params;
                fastcgi_param SCRIPT_FILENAME $document_root/$fastcgi_script_name;
                fastcgi_pass unix:/run/php/php7.4-fpm.sock;  # Ensure you use the correct PHP-FPM version here
                fastcgi_param FQDN true;
            }

            location /*.js {
                index pihole/index.js;
            }

            location /admin {
                root /var/www/html;
                index index.php index.html index.htm;
            }

            location ~ /\.ht {
                deny all;
            }

            # turn on the HTTP-to-HTTPS 302 redirect
            if ($host = YourDNSServerIPaddress) {
                return 302 http://YourDNSServer$request_uri;
            }
            return 302 https://YourDNSServer$request_uri;
        }

        #########################################
        # now let's do the same same for port 443  
        server {
            # note the http2 verb added here
            listen [::]:443 http2 ssl ipv6only=on;  # Note that we enable H2 support, because why not 
            listen 443 ssl http2 default_server; 

            server_name YourDNSServer;
            
            # I always like using the FQDN instead of an IP address
            if ($host = YourDNSServerIPaddress) {
                return 302 https://YourDNSServer$request_uri;
            }
            # Here comes our Let's Encrypt TLS certificate.  These lines were automagically added by Let's Encrypt CERTBOT
            ssl_certificate /etc/letsencrypt/live/YourDNSServer/fullchain.pem; 
            ssl_certificate_key /etc/letsencrypt/live/YourDNSServer/privkey.pem;
            include /etc/letsencrypt/options-ssl-nginx.conf;
            ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; 

            # enable TLSv1.2.  I am seeing it negotiating TLS 1.3 when accessing PiHole's UI via the browser
            ssl_protocols TLSv1.2;

            root /var/www/html;

            autoindex off;

            index pihole/index.php index.php index.html index.htm;

            location / {
                expires max;
                try_files $uri $uri/ =404;
            }

            location ~ \.php$ {
                include fastcgi_params;
                fastcgi_param SCRIPT_FILENAME $document_root/$fastcgi_script_name;
                fastcgi_pass unix:/run/php/php7.4-fpm.sock;  # again, ensure you have the correct PHP-FPM version
                fastcgi_param FQDN true;
            }

            location /*.js {
                index pihole/index.js;
            }

            location /admin {
                root /var/www/html;
                index index.php index.html index.htm;
            }

            location ~ /\.ht {
                deny all;
            }
        }