index.js

const express = require('express')

const app = express()

app.post('/sms', (request, response) => {
  let twiml = `
    <Response>
      <Message>hey there, thanks for checking out my demo!</Message>
    </Response>
  `;

  response.type('text/xml')
  response.send(twiml)
})

app.post('/call', (request, response) => {
  let twiml = `
    <Response>
      <Dial>
        <Conference>mlh</Conference>
      </Dial>
    </Response>
  `;

  response.type('text/xml')
  response.send(twiml)
})

app.listen(3000)

outbound.js

const twilio = require('twilio')

let client = twilio()

client.messages.list({ to: '(415) 881-1720'}, (err, messages) => {
  messages.forEach((message) => {
    client.calls.create({
      from: '(415) 881-1720',
      to: message.from,
      url: 'https://kevin.ngrok.io/call'
    })
  })
})