Cura Lulzbot Edition can't add Plugins?

I have Cura Lulzbot edition 3.6.8 and there seems to be no Marketplace/just a blank screen when I browse for plugins.

I am trying to figure out how to get the Mesh Tools > Split Model Into Parts extension. Or something with the same functionality you used to have in “old” Cura with just right clicking on a part.

I’ve never tried adding a plugin before, so maybe I’m just missing something.