How to change my ovulation day on the calander

Hey girls I was just wondering if anyone could point me in the right direction I feel like I’ve tried Do navigate this app and still can’t figure it out it generates automatically when I’m projected to ovulate but it’s wrong, I ovulate late in my cycle so that throws everything off a little bit I’m able to mark when I have a period but it won’t allow me to change the ovulation day? Tia!!