recording 4 tracks

I am trying to record four tracks at once, through my Allen & Heath mixer using usb out.
How can I record this way, and be able to mix afterwards?
Not sure how to set up Cubase for this.!
Thanks for any help.

Devices-Device Setup-VST Audio System, select the correct ASIO driver. Devices-VST connections set up 4 mono input busses assigned to the 4 inputs you’re using. Add 4 mono audio tracks with the various inputs connected.