How to migrate a site to Node.js?

Question

Node.js

Guys tell me how to transfer the site from one hosting to another. The site is written in Node.js backend. Or rather, I want to transfer from live to the dev server (copy) so that you can make changes and then upload it to live. The site works with the MongoDB database.
Node.js installed on a server (Ubuntu) created a database, uploaded a dump, uploaded files, registered the config, but nothing happens, it just writes the error "ERR_CONNECTION_REFUSED", it seems that it simply does not see anything. Npm yuzal did rebuild, start, etc. but there are no changes.
I myself write in php, but suddenly a project on node appeared and here I lack knowledge and didn’t google anything.

Answer 1

Everything turned out to be trite, just instead of the IP address of the server, you just had to register localhost in the request to the database, it helped me personally.

Answer 2

ERR_CONNECTION_REFUSED

This is not about a node at all, your connection is not rising somewhere, figure out where, where and why.
Maybe the config is not the same, maybe firewalls. maybe the port is not open and so on.
It is difficult to advise more on your question, since you have not written any other necessary information.