index.js

'use strict';

const express = require('express');
const bodyParser = require('body-parser');
const app = express().use(bodyParser.json()); // creates http server
const token = 'test'; // type here your verification token

app.get('/', (req, res) => {
 // check if verification token is correct
 if (req.query.token !== token) {
 return res.sendStatus(401);
 }

 // return challenge
 return res.end(req.query.challenge);
});

app.post('/', (req, res) => {
 // check if verification token is correct
 if (req.query.token !== token) {
 return res.sendStatus(401);
 }
 
 // print request body
 console.log(req.body);

 // return a text response
 const data = {
 responses: [
 {
 type: 'text',
 elements: ['Hi', 'Hello']
 }
 ]
 };

 res.json(data);
});

app.listen(3000, () => console.log('[BotEngine] Webhook is listening'));