Trigger an alert, tap a button on the fake phone, and watch the postback hit the webhook and change the transaction state. That round trip is the thing SMS cannot do. Toggle the fallback to see what a non RCS recipient gets instead.
| ID | Merchant | Status |
|---|
Tapping a button posts { suggestionResponse: { postbackData } } to
POST /webhooks/rcs, the same shape Google RBM sends. The server splits
action:txnId, updates the transaction, and replies into the thread.
Tap the same button twice to see the duplicate guard, since buttons stay live forever
in a real thread. Watch the terminal for the server log.