Your XPro-C Godox trigger speaks a different "language" than the radio receiver in the Canon 600EX-RT flash. You can't control the 600EX-RT directly via radio with a Godox trigger. To control the 600EX-RT with your Godox triggers you need a compatible Godox *receiver* attached to the hot foot of the Canon flash. For a long time, the only such receiver available was the X1R-C. The new Godox X2T-C is a transceiver that can be used as either a transmitter or receiver. Be sure it is set to "receive" instead of "transmit" when attached to the hot foot of the canon flash.