Expanding the reach of my express.js server to account for multiple internet services

Question

I want to set up a domain, but I have to migrate it from an express.js server I currently have this

app.listen(3000, 'ip', function () {
  console.log('Listening to port:  ' + 3000);
});

and I was wondering if there was any way to chat this so that anyone can access it (I can deal with whitelisting or something else seperately)

I've tried looking it up and I couldn't find anything helpful