WUXING Electric Bicycle Thumb Throttle, FT-21X Finger Throttle Accelerator, Speed Control for Ebike Pocket Razor Scooter Accessories Part, 12-72V Universal (Normal Plug (SM-3Y))

I suspect AddMotor uses a different pin mapping for their +5V, (-)Negative, and speed signal than this plug, possibly all plugs, and they do not sell a thumb throttle so I had to order one. Simply cutting the plugs alignment key with a razorblade allowed me to plug it in with a different pin on top, and then the throttle worked. Easy fix

Kept getting an error code and would not engage motor.

I accidentally smashed my original thumb throttle. Oops. This one is affordable and works great! The red/black/yellow wires don't exactly match the red/black/white wires from my controller. But I connected the reds, the blacks, and the yellow to the white and it worked fine!

Carefully review the specs you need, I had to mod the part to work, once modded works great!