Window Pivot Pin

Hi. A pivot pin is entirely missing an a double-hung window in my apartment. The spring clip is still in the track, but without the pin, obviously, the window won't grab the clip. However, in this window, the pivot pin is either hidden behind a cover, or part of a part that slides in (and acts as a cover) I can't get through the cover to see how the pin attaches. Perhaps the pin and cover are one part, and slide in? I'd be thrilled if you had this part for this brand window, and could tell me how it attaches.

Thanks so much.