I cant focus im loosing my mind

hi guys!!

im a college student currently studying photography, i've had this recent problem with flying birds and especially yesterday while photographing a dog catching a frisbee and my god it doesnt focus i dont understand how to do it :-(

i have a Nikon Z6 II and i usually use the focus point a square with dots around it (its circled in the photo) and it hasnt worked well with all manually so i switched to auto shutter speed and gues what nothing changed, it kept focusing the background, i have a button i usually hold to keep continuosly focuaing the subject and i try to follow the subject with the focus point. i tried to pu animal detection on but it focused only in some parts, not the best for fast movement i guess so i need help you guys, how do you do it on animals that are running?

its making me angry seeing all these unfocused photos