I recommend against wasting time on this non-functional add-on.

When I click on the icon in the address bar, the VLC window pops up and momentarily shows the video on the web page in the play list. Then it disappears from the playlist and nothing plays. A waste of time. I am now using "Open in IINA" which works correctly but loads IINA instead of VLC. IINA is a better video player than VLC anyway.