I don't know what to think as there is no icon available at all anywhere so I can't say it installed correctly. I bookmarked the options page so I could get to that but the hide icon is unchecked so it should be there I would think. If there is no icon is it not installed correctly?
Edit: I did find it in the dropdown menu where the three dots (...) are in the site address. If you right click on it you get the option to remove it form the address bar or manage it. If you remove it does it show up in the tool bar?

Fake location doesn't work with Firefox 60.
Not even with this extension demo.