Bf is important bt in certain circumstances u can use formula... I will suggest lactogen to use

Hi Rani baby is already 4 months old and by now your milk is well established, Why do you think your milk is not enough? World health organizations recommends 6 months of exclusive breastfeeding.

U should keep on latching ur baby,more the baby will latch the more milk will come.Read the following articles
Suggestive Diet For Lactation
Remedies To Boost Breastmilk Supply