linking sound from PC to output from UR22c

So I can send a microphone and guitar through the UR22C to OBS for a live stream and merge it with a spoken word USB microphone attached to the PC (along with video), but we now want to make it a live performance too. I know that the guitar / microphone in the URC22 can be sent to speakers attached to it (although have not tested this yet) but can one send the sound from the PC (e.g. from the other microiphone, or from a video playing) to the output of the UR22C so people can hear sound from the PC on the big speakers we plan to attach?

If it is possible, how do we do it, i’m a bit new to all of this.