If your baby refuses to nurse you should:
Reach out to an Infant Feeding Specialist and a pediatrician to make sure nothing else is wrong, to make sure baby eats and to ensure that you do not form engorgement, mastitis, or a breast abscess.
Make sure baby has some other way to eat (such as a bottle, a sippy cup, medicine cup, or syringe). Contact your pediatrician and go to the hospital if they have gone more than a few hours without feeding and/or have a reduction in dirty and wet diapers.
If your baby is able to drink expressed breast milk, baby wear your baby to make sure that you keep them comforted, resting, and keep your body in sync with their immunity needs, and express your breastmilk at any feed that they do not latch and suckle efficiently.