Also keep in mind, most guppies are already super inbred. Low quality of life. Especially if they are feeder guppies. So many of them die super quick. I had to swap in new males when they would die.
I made sure there was lots of thick vegetation to help preserve the new borns. If not they will eat them as they are giving birth. You want to feed them around 5 times each day, with smaller amounts because they are so fat with babies inside. Just need to make sure you are doing we fairly often. Also they say 12 hrs min of the light being on. Some have 2-3 babies survive and others have 20-30 survive. It’s very hit and miss with these creatures.