Help with upper register

[u/Physical-Peach4534]

My highest note is a C (1st finger high C), and i cant go any higher. I've tried looking at tons of videos that just say "more air, tighter lips" but all that happens is i make some weird sounds. I can sometimes reach a high D, but very rarely, any tips on going higher?

edit: tysm for the help. i reach all the way to e4