Hi @ashleyv
There was a recent post from @mtgardn who also uses Zotero and I provided a Scrivener project you can try to get working (read the rest of that thread too):
Make sure you create a synced.bib file using BBT as the first step.
You need to install pandoc, recommendation is to use homebrew to do so. I also demo using the Alfred workflow “supercharged citation picker” which is similar to Zothero[1].
The sample project has compile formats for 4 different outputs, you can study them. There is a Metadata file at the top of the binder, this is used to specify author, title and some paths to the bibliography files (the project itself puts them in the same folder the markdown file will be created in, but you can specify different paths if you want). You need to edit the compile post-processing pane to make sure the paths to pandoc and other tools are correctly set up, then it should just all work.
[1] I prefer it simply because it uses the bib file directly, so it is compatible with both my preferred manger Bookends and Zotero and JabRef and the manager itself doesn’t need to be open; but if you add a ref you need to sync before it shows up in the floating window.