How do you bind the third keybind? I'm using the wizard origin and I don't know how to use the wither skull shooting ability as in the keybinds there is no 3rd power... I have tried the origins keybind mod but the third keybind did not bind to it and nor did any of the others. PLEASE HELP!

For a bound more than secondary, try Load/Save hotbar, and Show Spectator Outlines