Twilio developer evangelist here.
You can initiate a message with the bot using the Twilio REST API in the programming language of your choosing, like JavaScript, C#, PHP, Ruby, Python, or Java.
curl -X POST https://api.twilio.com/2010-04-01/Accounts/ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX/Messages.json \
--data-urlencode "Body=Hi there!" \
--data-urlencode "From=REPLACE-WITH-YOUR-TWILIO-NUMBER" \
--data-urlencode "To=+NUMBER-TO-TEXT" \
-u ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX:your_auth_token
This cURL request initiates an outbound SMS. Then if you configure the Twilio number to an Autopilot bot, when the user responds, they will enter in to the bot dialogue.
You can publish the bot to multiple numbers either in the phone number console for each number and get the responses in the Autopilot request like with Memory.