How to combine node-turn with existing express app

I need to use a own TURN server for peerjs and I found that node-turn would be a better solution for that. But I would like to use the turn server along with existing express server. There is a way, we can provide the port at node-turn.

var server = new Turn({
     listeningPort: 8001
  }
});

But when I host this app on a server, listening on different port does not work. Therefore I have to implement this in another way. Thanks in advance.