Canon R series mirrorless camera doesn't support the external AF, and it only allows to use of its internal AF.
Unlike some older DSLR cameras, Canon mirrorless cameras generally do not have a dedicated port to connect an external autofocus system/module. This is related to the mirrorless camera principle, for which we currently have no solution.
BTW, correct AF in the flash or trigger, but you find that the camera does not activate the autofocus assist beam, this is because the camera has a correct autofocus already. That's normal, this is how it works.
Yes. The XPro-C had a firmware update (v1.8) to make it compatible with the T7 and T100.