Ah, Yeah, sorry for the confusion. The on screen buttons aren't bound to keys. It would have taken me two seconds to either update the sprites or bind them to the keys but I didn't do either and I didn't bother with QA testing so I hadn't realized how confusing it would be.
The keys aren't bound. Don't try using your keyboard F1 F2 and F3. Just click the buttons on the screen with your mouse. I'll update the instructions to more clearly reflect that. Thanks!