No message response

in web hook router

`const promises = req.body.events.map(event => {
	return line.client
	.replyMessage({
		replyToken: event.replyToken,
		messages: [
			{
				type: 'text',
				text: event.message.text
			}
		]
	})
})
Promise
.all(promises)
.then(() => res.json({success: true}))`

It should echo the message but nothing and without any error :(
