Install and migrate NodeJS web app

I need someone to do this NodeJS web application installation:
1) migrate NodeJS web application from staging digitalocean VM to another live digitalocean VM
2) The live digitalocean VM will need to host on a sub-domain, currently the main domain Wordpress is running on another VM (not in digitalocean). Hence, need to setup this sub-domain to host this NodeJS web application in live digitalocean VM