How do I manage if my baby doesn't like "tummy time? "

Brief and frequent. Have frequent brief periods of tummy time, allowing slight frustration but stopping the tummy time if she gets really annoyed. Have stimulating toys nearby for her to look at, reach for and eventually scoot towards. Put a mirror in front of her when she's on her tummy. Pay attention to her cues and be flexible.
Try but don't worry. We encourage tummy time for infants to help build the upper arm strength needed to roll over & push up. I think a lot of this is based on trying to meet motor milestones that were standardized in the 60's and 70's when kids belly slept. I'm not aware of any similar study of backslept babies. I would not loose sleep if baby hated tummy time. In the end they will catch up.
Do Not Give Up. Tummy time is important to help promote upper body, arm and neck strength and coordination, in an era when babies spent much time on their backs. At first, many do not enjoy the experience, but be patient. A few minutes 3-4 times per day is a good way to begin. And if your baby does not do " tummy time'? They will still grow up and do all the normal things. Tummy time may just make it easier.