We are currently working on fitting our TMNT Arcade1Up with a retropie and have gotten stuck. We have all of the 4 players installed properly (as far as we can tell) and have worked on button mapping more times than we can count. The one thing were are not seeing is the hotkey assignment. Shouldn't this automatically pop up during the setup? Or is there somewhere we can turn the hotkey feature on to assign a hotkey command? YouTube videos all show the Hotkey Enable assignment there at the start. We are beyond confused and frustrated (and also are struggling to get the joystick to actually move our characters in-game after thinking we had it).
To sum it up, we are noobs. We thought this would be a little more straightforward. Please send help.