The Messaging tab keeps the member's SMS conversation beside the record so the next agent can read the thread before replying.
Open the thread
Find the person under Members, open the record, and select Messaging.
Check consent
If sending is blocked, record SMS consent on the call. A STOP reply disables sending until the member opts in again.
Send and watch for replies
Write the message, click Send SMS, and keep the member record open while you walk them through the next step.