Simple Nginx proxy reverse configuration    add the file proxy.conf in /etc/nginx/conf.d/       proxy_http_version 1.1;   proxy_set_header Host               $http_host;  proxy_set_header X-Real-IP          $remote_addr;  proxy_set_header X-Forwarded-For    $proxy_add_x_forwarded_for;  proxy_set_header X-Forwarded-Proto  $scheme;  proxy_set_header Upgrade            $http_upgrade;  proxy_set_header Connection         "Upgrade";           Configuration for the domain simple      server {   listen 80;   listen [::]:80;    server_name example.com;    location / {    include    conf.d/proxy.conf;   proxy_pass http://192.168.123.321:3000/;   } }