nginx reverse proxy config

domain.conf

server {
      server_name example.com;

 access_log  off;
 error_log off;

location / {
  proxy_pass              http://my.synology.ddns
  proxy_set_header        X-Real-IP       $remote_addr;
  proxy_set_header        Host  $host;
  proxy_redirect          off;
  proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
  proxy_connect_timeout   90;
  proxy_send_timeout      90;
  proxy_read_timeout      90;
  client_max_body_size    10m;
  client_body_buffer_size 128k;
  proxy_buffer_size       4k;
  proxy_buffers           4 32k;
  proxy_busy_buffers_size 64k;
}
error_page 501 502 503 /index.html;
location = /index.html {
        root   /var/www/html;
}

    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

}
server {
    if ($host = example.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


      listen 80;
      server_name example.com;
    return 404; # managed by Certbot


}