Using self centering sticks for a VTOL

Hi, I’m using a skydroid T12 transmitter with self centering throttle sticks for my VTOL. I have read that for self centering sticks, I need to have this parameter PILOT_THR_BHV set to 7. But i don’t see it in my full parameters list. I have uploaded arduplane firmware and enabled q parameters for the VTOL. How do I use my transmitter with this setup, as I have seen many people use self centering sticks? I have a cube orange flight controller.