I was able to set late policies before: e.g. each day late = -20%. But I've forgotten how to do it. When I look up h(Iow to do it I see instructions for the "new gradebook" but those don't seem to apply to my situation - it says to go to Grades then open Settings, but I don't have the settings icon.
I vaguely remember doing something like going to Assignments then editing individual assignments, but I can't remember how I got to the late submission settings. (The assignments are generated in My Lab / Mastering - maybe the settings were there, but I don't think so).