Multiple fisheye cameras

I have two fisheye cameras rigidly mounted on a rig with GPS and I would like to process them together with Pix4D.

How can I manually configure a rig composed of two cameras? I know an approximate relative orientation of the two cameras (boresight) which I also would like to refine. I cannot find how to do it in the Pix4D mapper for linux. Is this possible?

Thanks for the support