Deactivate the cube's compass and use IMU for Heading

Hi !

I come to because I can not deactivate the magnetometer of my cube and use the IMU for HEADING.
I put the parameter EKF2_MAG_TYPE = NONE.
But I can no longer use missions.

I have to deactivate it because my frame is made in steel. I have disturbances.

Can you help me ?

I don’t think the IMU can establish your bearing without a compass.

I looked at what PX4 offered as solutions, but impossible to switch to mission mode, I remain blocked in manual (vehicle armed).