When you complete the 2020 return enter them in the MY INFO section and READ the screens carefully ... hopefully you have the SS# by now because it must be entered. Watch for this screen ... it tells you exactly what to do.
Congrats on your new baby girl. A dependent is entered in My Info. Since your child was born in 2020 make sure that when you get to the screen that asks how long she lived with you that you choose WHOLE YEAR. You have to do that for a newborn so that you get any of the child -related credits you are eligible for. You are eligible for chid-related credits even if the child was born on December 31. And when you get to the oddly worded question that asks if the child paid for over half her own support say NO.