Select Spacebar shortcut repeats Undo/Redo

This whole problem is avoided if I don’t use the Undo and Redo icons near the top left of the screen. In SketchUp for Web, are there single key shortcuts for Undo and Redo? (ctrl-z and ctrl-y are too cumbersome). Or can custom single key shortcuts be set for Undo and Redo, either in SketchUp for Web or Windows?

Thanks