Midi Keyboard Controller to USB Mixer and PC Connection

[Bremerbnj]

I have an Arturia keyboard with only a usb and mid out port. I purchased a Behringer q802 usb mixer and a Mac Mini M1 using Mainstages software and I want to use in live performance. I thought I could use the usb mixer as my audio interface. I also thought the connection scheme would be simple but I’m struggling with the connection scheme to get signals from keyboard/Mac MainStage to mixer to FOH? Or do I still need to use my Focusrite interface?

I also have a Kurzweil workstation with midi and usb Ports. Could it be used as part of the whole connection scheme?

TIA

Thanks,
Brian