can i restore deleted messages

IF you have not activated iCloud messages and IF the delete messages are in your back you can restore your iPhone from your backup and retrieve them. You will lose any data added since the date/time of that backup. Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

Go to:

Settings > Your Name, iCloud, Media & Purchases

Tap iCloud

Are Messages turned on?

If yes, deleted messages are gone

If no, and you have a backup from before you deleted the messages, you can restore your phone from backup. But be advised that your phone will be restored to the date the backup was made, meaning messages sent or received after the backup was made will be gone.