You don't need to! Your milk doesn't come in for 3-5 days your baby needs colostrum after birth not milk. You don't want to over produce. And your supply won't regulate for up to 6-8 weeks after birth. There is no need to try to up supply if there is no issue
Don't even worry about your supply! Baby will get colostrum at first and you won't start to produce for 3-5 days after birth. The more baby nurses, the better your supply!