Trying to send Key Inputs - Uncaught Error: ERR 0x3401 in function "tap"

Just looking at the code again, and one thing that is an issue (but not the whole problem) is that you're calling tap slightly wrong:

// kb.tap = function(keyCode, modifiers, callback)
  kb.tap(kb.KEY.A, kb.MODIFY.LEFT_GUI, kb.MODIFY.LEFT_ALT);

So the third argument is expecting a function to call back but it's getting a variable - this is what you want I think:

kb.tap(kb.KEY.A, kb.MODIFY.LEFT_GUI | kb.MODIFY.LEFT_ALT);

But I just tried with a Puck here and the code appears to work. I've tested it on Android, iOS, Windows 10 and it all works...

But I just tried Windows 11 and for some reason it doesn't show the device (Windows 10 shows loads of devices, but Windows 11 shows hardly any for me). I'll see if I can figure out what the problem is...