How do I use an AudioBox USB 96 to get the sound from the StudioLive 32.4.2 AI to OBS?

Our church uses OBS for Live Streaming. We get the audio from our StudioLive 32.4.2AI mixer by ruing a coection from the tape out ports to a BlackMagic Intensity Pro 4K capture card which OBS recognizes as an audio input source. However, we get a low humming sound on the recording, so we were advised to instead coect the sound from the mixing board via the 1/4 inch Main output ports ruing to a AudioBox USB 96 device into the computer. This way we use balanced XLR cable to shield the humming. But I can't figure out how to make that work with OBS. OBS doesn't recognize the AudioBox as an audio input source.

Can anyone help me with guidance?