>>40613537 (OP)Passing is easier before puberty but not impossible afterwards. Recall most transitions historically were done after puberty outside of a few seconds workers in third world countries.
You're probably baby trans and aren't at the point where you could be expected to pass because it takes time for changes. I didn't even get fat redistribution until like 3 years in, and everyone's body is different. Unless you're like bald you're probable going to be able to make it.
Most of passing is unironically doing your eyebrows, styling your hair, and choosing flattering clothes that hide the traits you're most dysphoric about while emphasing your good points. If you're 6'1", have bushy eyebrows, and linebacker shoulders and wear sleeveless tops, of course you're not going to pass. Same if you wear hoodies constantly. You need something to accentuate your femininity and hide your worst traits.
Mg experience isn't universal, but I transitioned at 23 and I pass now pretty consistently.