Baldur's Gate 3: How to solve Jaheira's Sanctuary

pin slotSpring plunger. with pressure pin and slot Steel version : body in steel class 5.8 black oxide finish, pressure pin in hardened steel, spring in spring steelHi - I'm trying to make a pin go up and down in a slot. I have a rectangular slot and a circular hole in a linkage. I want the circular hole in the linkage to move up and down