For zotero-mdnotes to work you'll need to install the following plugins.
You can install the plugin in Zotero as described here:
To install a plugin in Zotero, download its
.xpifile to your computer. Then, in Zotero, click “Tools → Add-Ons”, then drag the
.xpifor the plugin onto the Add-Ons window that opens
You can grab the latest version of
If you're using Firefox, make sure to right-click on the
xpi file and use the
Save as menu, otherwise Firefox will try to install the xpi as a plugin and will throw an error.