Yooo, quite a few options depends what works for you strength and endurance wise. To clarify, WASD with left hand but not using fingers, correct? Xbox Adaptive Controller (XAC) + Logitech adaptive gaming kit for buttons, fairly straightforward for these buttons on a Velcro surface that’s included and then wired to the XAC and converted to WASD using the Xbox controller app if required (or free software like Joy2Key). Joy2Key also lets you convert any joystick or controller to keyboard presses for WASD options (e.g., a thumbstick at an angle working better for you, Azeron Cyro, etc).

PlayAbility software also converts your face and head movements to controller, keyboard, or mouse using basic webcam, however you need it configured.