how do i know that my breast milk supply is enough for my baby my baby is 1.5 months old

A. you can check on the urine count and if it is minimum 6 to 8 times then not a problem and also check on the baby weight and if baby is gaining a minimum of 600 grams to 800 grams per month then it is a good weight gain and absolutely nothing to worry and not a problem otherwise you can alternatively give infant formula milk stage 1 using a bpa free bottle like babyhug