How to restore deleted texts

If you’re using messages in iCloud, deletions are permanent - Keep all your messages in iCloud - Apple Support

If you don’t use messages in iCloud, messages are part of your iTunes or iCloud backup and you could restore that backup. A restore replaces everything on your device with the backup file contents though. And backups are incremental and overwrite each previous backup, so the deleted messages may no longer be in your current backup.