You should be able to import this into Vroid Studio as a Vroid custom item after clicking "file" in the top left corner. It should show up under "eyelids" as a custom item. If it interferes with hair, you might have to edit the hair control points or the eyeshadow itself. The model wearing the eyeshadow is free to download in my shop, and his hair shouldn't interfere with the eyeshadow at all.