This can also be used for a new rescue dog since they may not know their name or you want to pick a new one:
Be in a quiet environment. Say the puppy’s name in a happy and fun tone. As soon as they look at you, give them a treat. Wait a few seconds then say the name again, wait for eye contact, and treat.
If the puppy looks at your hand and not your eyes, lift the treat to your eye.
If the puppy doesn’t look, ignore, wait a few seconds and try again. If they are still struggling, say the name and use a kiss or other sound to get their attention.
Remember to keep sessions short and sweet. But also keep in mind that this should take a few days to learn.