Doorkeep can text you and your team about calls. Texting has an account-level switch, the texts go to the people on your Call List, and there is a STOP/START opt-out that lives on your phone.
Two things have to be in place
Account-level SMS (account owner): under Settings → Phone, turn on Enable SMS Notifications. This is the master switch for the whole account. If it's off, no one gets texts.
Your place on the Call List: call texts go to the people on your Call List, not to a personal switch. Check the SMS Notifications section of Settings → Notifications to see what applies to you.
If texting is off, the SMS Notifications section says so: "Text messages are turned off for" your account, "so no call texts or callback reminders are sent," with a line telling you what to do next.
If you replied STOP
Carriers let you opt out of texts by replying STOP, and that blocks Doorkeep texts too. If you've done that, Settings → Notifications will show a notice. To turn texts back on:
Text START to Doorkeep's number.
Refresh the Settings → Notifications page.
Good to know
Call-notification texts go to everyone on your Call List who can receive texts, in list order. On Starter, the account owner is texted as well.
Lockout calls don't send texts. The details wait in the Call Log.
SMS is for notifications to you and your team. It isn't two-way texting with tenants.
What to expect
Only the account owner can flip the account-level master switch.
After enabling, you'll see a confirmation that SMS notifications are active.