There's actually a keyboard support in among us since it was integrated to pc, you just have to activate ''Mouse+Keyboard'', you'll only can use the mouse for do task, sabotage and etc, for move you use WASD, for kill Q, for enter a task,vent, use the emergency meeting, and open the sabotage menú (if you aren't on a vent) just press E, and for report a dead body use the key R.
I hope my comment helped you!