Really confused about importing parts from elsewhere (*.lbr)

I can see where I can import an entire project from various other systems. Great, but I am just trying to import a single part made available by the folks who designed it. Is importing parts supported in some way? I haven’t been able to find it in the UI.

The specific part I am interested in is the NodeMCU board. The Upverter parts library contains a couple of variations of that part, but the footprints are all wrong (that is, they don’t match the part that I actually have in my hand). The part file I have (from here: is an XML file that I suppose is some Eagle format. It has file extension .lbr.

I know I can ask Parts Concierge to supply this part’s schematic and footprint, but is there a way I can add it myself?