Can I retrieve deleted text messages on my iPhone?

Go to Settings/[your name]/iCloud. Is the switch for Messages turned on? If it is, there is no way to recover a deleted text message.

If it is off and you have a backup that was made before the text message was deleted you can restore that backup to the phone, however, this will replace everything on the phone with the contents of the backup; essentially it will set the phone to the state it was in at the time the backup was made.