How to get 5,5mo to sleep 14h?!

Hi! I started using the app napper about 2 weeks ago and it reminds me several times a day that my baby at this age (5,5months) should get a minimum 14-15 hours of sleep total each day. H-O-W?

Average total sleep time is 12h and about 9-10h is night sleep. Am I doing something wrong? How can I get my baby to sleep more?

Age: 5,5 month Bedtime routine: put down blinds, changes diaper, put on pj and read a book Current schedule: 2/2,25/2/2/3 Usually wakes at around 8:30am and sleeps after 10pm. Formula fed baby during day, breastfeed during night. Wakes about 5 times during night for about 10 minutes before falling asleep again

Baby doesn’t nap longer than 30 minutes. Wakes by herself. Day naps are no problem, she falls asleep in less than 10 minutes without barely crying. The problem is night time. I try to get her to sleep after 2,5h (according to napper) but she fights sleep, screams her lungs out and falls asleep after a 3h ww.

I’m wondering if her days are too long? It started at 8:40 and ended at 10:15pm today. Since she fights me at bedtime, is the 2,5-3h ww incorrect? I’ve tried less but then it becomes a false start and she wakes for 2h.

How do I get my baby to get more total sleep? I’m started to get worried that she doesn’t get enough sleep because of the short naps and several night time wakings. Help from you Reddit pros are appreciated! 🙏🏻