Why won’t my Mac and DAC play nicely together?

I’ve sent my Mojo audio déjà vu off for an upgrade. I thought I would just run my Mac through the Exogal Dac in the interim. Also sent my Chapmans back for a full upgrade to T9 status. Picked up a pair of of KEF Metas in the meantime. Oh boy. But that’s another story. 
When I go to the sound control setting, the Mac “sees” the Exogal but when selected, I get a message, “The selected device has no output controls.” I’m feeding the DAC via USB.  

I am fairly tech naïve so just may have missed something obvious. Any suggestions are much appreciated. Thanks
Thanks Eric. I’ll take a look-the link really appreciated. My search parameters didn’t pop this  Wasn’t kidding about being tech naive. Was busy teaching babies how to hold a spoon over a half century ago. ☺️
I am running Big Sur 11.1. I don’t get that option in the security panel. The no output message occurs in the sound panel. More cooking around seems to indicate it should’ve been fixed with this software. Also can’t get it to select in the audio MIDI set up. I’ll keep poking around
As I read this, the problem isn’t you don’t get sound, but that the dac won’t let you control the volume?

That’s not fixable in your Mac’s setup, but your player may. Keep in mind that if you let your player change the volume you are letting it rewrite the bits.