index.js

const express = require('express');
const app = express();
const port = process.env.PORT || 8080;

app.get('/', (req, res) => {
  res.send('Hello!')
})

app.listen(port);

Teste

var express = require('express');
var test = express();
var port = process.env.PORT || 8080;


//routes
test.get('/api/users', function(req, res){
	var user_id = req.param('id');
	var token = req.param('token');
	var geo = req.param('geo');

	res.send(user_id + ' ' + token + ' ' + geo);
});



//
test.listen(port);
console.log('test port: ' + port);