Once you add Clerk to your Slack workspace you will be presented with the following option:
You are now ready to send your first SMS!
Yes, our Twilio Integration is only available on the API Plan. Please reach out to firstname.lastname@example.org with the following pieces of information to activate your Twilio account:
Twilio Auth Token
Twilio Account SID
The phone number you’d like to associate Clerk with.
You can find the above information in your Twilio Dashboard: https://www.twilio.com/console