1month baby still now did not regain birth weight..but she wet the diaper per 6+ time and also poop is normal..then what to do regain the birth weight

A. What what do you have to do by regaining the birth rate that I’m not understanding after the child takes birth there is a certain weight and little bit of weight losses seen after delivery could be due to jaundice within first week after that it is evaluated that the childhood gain 500 g in a month if that’s not happening then check with your doctor and start giving formula to the child