Waves SuperRack Performer

Hello everyone,

Maybe it is really possible at all, but this will be the last that I am asking for help from this forum and hoping for some answers. Thank you in advanced!

I have tried Waves SuperRack Performer via Behringer Flow 8 and a Macbook Pro
As SOP, I plug in via USB cable and Audio Midi Setup was set to Aggregate device.

Waves SuperRack > SETUP = I set as the behringer flow 8 (Recording)
Tried on Channel 1 > Output to USB 3/4 (works fine, I can hear thru the monitor headphones from the mixer, in realtime)

But when I go to streamlabs OBS and set the Mic/Aux to Aggregate Device, there is no sound..

Am I missing something? Maybe I should give up and upgrade to XR18 as I watched from youtube that it can support using the plugins via Waves SuperRack.

Sorry for the long story, appreciated your effort reading this.