People are different so there isn’t really a normal.
One of my mates legit has zero facial hair and another one could grow a proper beard at 16.
Some people just don’t get much hair on their face or if they do it can be patchy. I think for u if it stays like this until 21 then it’s likely that that’s just how ure hairs grows.
So don’t fret about your facial hair, as there’s defo a lot of people in the same boat as u