How can I route my audio so that I can hear my metronome in Ableton but my audience cannot?

[elbonez]

I stream music on Twitch, using Ableton as my DAW and OBS. I use Soundflower to route the audio.
I want to be able to hear the metronome in my headphones, but I don't want it to be audible to my audience when I stream. Someone has suggested creating an aggregate device, but I really need specific step by step instructions with how to get this to work with Ableton and OBS.

Thanks so much for your help