Have tried both in game settings and editing the xml files.
According to http://blog.codemasters.com/wp-content/uploads/2019/05/Multi-Input-Device-System-for-DiRT-Rally-2-0-Master.pdf
The other axis are on the pedals (Meca cup 1), and they get calibrated.
Seems the app can’t detect the axis for the wheel on a separate usb device.