how i make passtrought platform

I’m making a 3d platform project that bring the castle of castlevania aria of sorrow just for z’lols(and for level design practice)
and in this game(and a lot of others platform games) there’s a platform that you can pass trough if you go in one direction(in this case from down to up) but you can land on it,and go thought it if you crouch and press space