So I'm animating an aboject following a motion path. When I open the Graph Editor it has 2 keys: one at the beginning, and another at the end. Is it possible to insert a key in between? I've tried using the Insert Key tool, the Add Key tool, and Add Inbetween, but none of them seem to do anything. I tried the same on a simple cube moving, and none of those tools work on it either. What am I doing wrong? Do these tools work?

Thanks,
-dann