On Fallback → Template Mapping, use the Preview action in the manage table. It opens a mobile-style modal showing how each channel step may look. Preview is available only when every channel in the sequence has a template selected.
When Preview is disabled #
If any step is missing a template, Preview is disabled with a message telling you which channel needs a template. Edit the flow and select all templates first.
RCS previews #
RCS steps use the same rich-card, media, and carousel bubble layout as RCS template manage, so you can verify rich content appearance before go-live.
After preview #
Still send real test messages to your own number and confirm behaviour in Delivery Reports—preview shows template layout, not live delivery routing.