Configuration NGINX with NodeJS

node.conf

map $http_origin $cors_header {
    default "";
    "~^http?://[^/]+\.sundi3yansyah\.id(:[0-9]+)?$" "$http_origin";
}

server {
    listen 80;
    server_name node.sundi3yansyah.id;

    location / {
        proxy_pass http://188.166.228.104:1234;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_http_version 1.1;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $host;
        add_header Access-Control-Allow-Origin $cors_header;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-NginX-Proxy true;
        proxy_redirect off;
    }
}