So, I bought my ESO physical copy in 2017, and have been playing since.
I now want to buy a plus membership through Steam, because it's WAY cheaper for me there, but when I try to pay it says I don't own the base game so I can't.
I have my ESO and Steam accounts linked, and used the 'Add non-Steam game' to add ESO to the Steam app, although it seems this option is only to add a shortcut and not to link the actual game.
Is there another workaround I'm not aware of?