how do I know the coordinate direction of the joystick of quest 3

hi guys, I am working on oculus reader aim to read the pose of the joystick of quest 3, I did got the pose information, however I am confused about the direction of the y and z axis of the joystick. when i try to move the joystick along its y or z axis, it seems i cannot get the correct direction of y and z axis, always has a deviation. so i wonder if there is any official docs or any advice of the coordinate direction of the joystick? really thanks a lot!