Sorry for the hassle. I recommend that you allow the accessibility request. That will enable Time Out to detect when you aren't using your keyboard. Don't worry, it doesn't look at what you actually type; it just want to know that the keyboard is being used, like with the mouse or trackpad, so it can detect natural breaks.

In the next version I'll avoid requesting access if you disable it or use a different idle detector. Until then, it'll prompt on each launch until you allow it.