I tried to follow this, but I'm failing at seeing where the F-Curve modifier Settings are displayed. Once more, the Blender UI is failing me with its logic.
According to the Manual they should be in the Sidebar! No luck in either 2.79 or 2.80.
Blender 2.79
I Went to the Graph Editor and selected Key > Add F-Curve Modifier > Generator. The Cube in my scene disappeared and where in the Sidebar there should have been settings, there were none:
File for 2.79
Blender 2.80
Blender 2.80 is even more confusing since they redesigned the Sidebar but didn't update the Manual to match. I followed the same steps but didn't even know where to look for Settings.
File for 2.80
How does one edit an F-Curve modifier?