Flow Solution:

Easy SMS-Based Authentication with Bots

Watch how Bots, Flows, and Live Agent Chat work seamlessly together. Einstein Bots calls out to Flows that in turn call out to Twilio's Authy service.

https://medium.com/@alexedelstein/using-flow-with-chat-bots-and-sms-via-twilio-and-authy-d400e83260e7