How do I wake up my newborn?

Lucia • Luciaa💏
He's 10 days old and when I feeding him he falls asleep a lot so I have to be waking him up. But right now he fell asleep after a bath and hasn't woken up even if it's past his feeding time. Its been 2 and a half hours since I last fed him. He's breathing and he's ok he just gets mad and falls back to sleep.