Tiltrotor Vtol with 3 motor

Hi I would like to build a VTOL like in the video. When transitioning to fixed-wing mode, I want the two motors in the front to rotate, while the rear motor remains fixed. However, I’m not sure which motor will rotate to which side, depending on the flight controller. I don’t know which motor will be the first, second, or third during flight. I’m also unsure about q_frame_class, q_frame_type, and q_tilt_mask. I would be very happy if you could assist me with this.

Probably start here:

Good luck.