

The first question after “it’s not working!” Is always “what isn’t working?” followed by “show me what you were doing”.
Used to have to deal with getting information out of customers that were having issues with our app (as a software dev, not sure why that was my job). Eventually we just asked for a video of what they were doing first thing when anyone called.
There’s so many tech illiterate people out there, even young people who grew up with their phones often don’t really know how to use it besides opening apps.
The person you replied to is correct, and your link confirms it:
The extension does not just have this access, it has to request it from the user first.
Of course, an extension can request access to all browsing data, but Firefox will tell you about that before you install it. And better still, the extension this post is about, doesn’t even request this: