I am guessing that is a Blind app reference?
Personally I have to be blowing air out my nose at a pretty unsustainable rate to prevent water from coming in, so if I'm doing serious swimming I use clips. Not exploring this option when I was a kid made me resent and hate swim classes even though I loved being in the water.
Another tip that comes immediately to mind is try using a swimmer’s snorkel. At first, it’ll be really difficult to keep from water going into your nose but after a few practices, your nose and it’s canals will block out water as a reflex, enabling you to breath through your mouth the entire swim. Hope this helps and sorry for English!