I've clicked on every icon on the screen with no results. Search returned nothing useful, too.
Not sure quite what you are looking for, perhaps you could describe the action you want to control, then maybe I can help you find the right place to go. What do you imagine the "user control panel" does?
Click your Avatar in the top right corner and go from there.
AHhh I see said the blind man! The user control panel for this website, not for Sketchup, duh.
You might say I could not think outside the Box.
Thank you, Box!