Retrieving deleted text messages

You can restore messages you deleted for up to 30 days.

1. Go to the Messages app on your iPhone.
2. In the Messages conversation list, do one of the following: Tap Edit in the top-left corner, then tap Show Recently Deleted. ... 
3. Select the conversations whose messages you want to restore, then tap Recover.
4. Tap Recover Messages.

Recover deleted messages in Messages on iPhone

Have you looked in the Recently Deleted folder in the Messages app?

Available only on iOS 16 and above.