I’m really sorry but I don’t know what this means.

Same with this. I’m googling aux send but still finding it hard to understand.

Gotcha. So I need to send the midi clock separately, not through the mixer.

I think I actually have one of these. But this would mean that the laptop is controlling the clock.
What if i have no laptop connected? Could I go
looper → usb/midi din → computer
and
looper → usb/midi din → volca
?

Great. I have one of these
https://images-na.ssl-images-amazon.com/images/I/41Po3qr14aL.AC.jpg

I expect that would work?
I find it hard to work out whether, for instance, my Pocket Piano is sending midi clock data or actual midi notes.

Could I set the looper to always be the midi clock master? Then when I connected my computer would take that as the master?

Thanks!