How long

How do you get your baby to latch on my baby is a week and 3days and will not latch on for nothing he started off on the nicu so they gave him bottle for the time he was there now he won’t latch on and cry whenever I put my boob in his mouth I pump and give him the breast milk instead but I really want him to latch on how long does it take for them to latch and yes I seen a lactation consult twice