Need Help!!!

Iman

My baby is 3 weeks old. I’m a new mom. After delivery i got no milk for like 4 to 5 days so i had to put my baby on formula milk (which i never wanted) but after few days milk came but still i cannot produce more than 2 oz (both sides) once or may be twice a day. Can anyone help me with that? Like how can i produce more milk??