How to use Overbridge sidechain for processing

Hi,

Can someone walk me through the steps of sending audio through one of the synth channels on the Analog Rytm?

I want to send the output of a vst-plugin from Ableton live 9.5,
through Overbridge 1.10 using the sidechain function in the overbridge plugin,
through one of the synth tracks on the Rytm (ex BD1) and add some overdrive,
and then record it back into ableton.

I can see them doing it in this video around 8:00, but I can’t get it to work:

Thanks,
hjesper