[User 224999]

Mike best way to find right code for widget is to enable "debug logging" in kodi, and start "open" in addon settings for "Skin helper widgets".
Almost all widget in plugin://script.skin.helper.widgets/?action=albumslisting are populated...missing for me only
action=favourite&mediatype=movies
action=favourite&mediatype=tvshows
action=favourite&mediatype=artist
action=favourite&mediatype=songs
action=recommended&mediatype=songs
All working like this

Code:

plugin://script.skin.helper.widgets/?action=random&mediatype=songs&reload=$INFO[widgetreload-music]

I will update the readme for the widgets addon later this week, it's indeed missing lots of info
There's btw a typo in your paths, it's artists and not artist