How to recover deleted text messages?

Go to Settings/[your name]/iCloud. Is the switch for messages ON? If it is there is no way to recover deleted messages.

If it is OFF and you have a backup that was made before the messages were deleted you can restore that backup. Doing so will overwrite everything on your phone, not just those specific messages.

You can also try asking the recipient to copy the message and send it back to you.

See→Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

It's not easy, and it comes with a big downside for most users.

Your iPhone would need to have been backed up while the messages were still on the phone......AND......there must not have been any more backups made of the iPhone after the messages were deleted from the iPhone.

Why? Backups simply keep a mirror image copy of your iPhone, so if you delete a message, the very next backup will pick up that action and delete the message from the backup.

For example, say a message was on your phone on August 1 and a backup occurred that day. OK so far. But, on August 2, you deleted the message and the August 2 backup would have picked up that action. So, the message disappeared from the backup on August 2.

Further, lets say the iPhone backed up with the message on the phone on August 1 and no more backups have occurred since that date. Then, you could restore the backup to the iPhone and message would be included in the restoration. But.......you would lose any of the data that you added to the iPhone since August 1, because your phone would look like it did on August 1.

So unfortunately, things are not nearly as simple as they might appear. In most cases, the message is deleted from the backup before the user realizes the mistake. So, the message has already disappeared from the backup so there is nothing to restore.

In almost all cases, it is far easier to ask the other person in the message to send it back to you.