Load KML into QGC

Hello there. Does anyone know how to get a KML into QGC to use in mission planning, even just as a background reference layer? I’ve tried different projections, points/lines/polygons, simplifying geometry, everything I could think of and it never works and always throws an error. I tried plugging the HereLink controller into my PC and my laptop like some instructions I found online said to do, and neither of my windows 10 computers seems to fully recognize the device bc there’s no QGC folders in the ‘Optimus’ device that shows up in windows explorer after plugging in the controller. I just get a device named ‘Optimus’ that is empty and when I try to copy files to it it doesn’t let me. Thanks for any advice ya got.