demo.coindoodle.com

 location / {

                #proxy_pass http://51.75.252.118:8080;
                proxy_pass http://127.0.0.1:3000;  # use your app port
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;

pm2 start index.js --name demoapp

pm2 save