Age Fixing

So I was a dumbass kid and I wanted to put some stupid age on TikTok. I tried fixing it and everything and I still couldn’t do it because all they do is they tell me to use TikTok support, I have tried it and I ultimately just want to give up as a whole. Any fix for this (I’m over 16 but under 20 I don’t wanna say my age on Reddit :P)