how can I retrieve a phone meassage that was deleted on iPhone 12

Unless you house your messages in iCloud, they are saved on your iPhone backup. Restore that backup to retrieve the messages that were present when the backup was created.

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

Or, with iOS 16:

Delete and recover messages on your iPhone or iPad - Apple Support

If your phone is running iOS 16, check the Recently Deleted folder.