How can I access the correct XPI from a Firefox fork?

Question

I am running a Firefox fork on GNU/Linux that AMO does not recognise. So instead of giving me XPI links it gives me buttons to "Get Firefox Now!".

Digging into the HTML source I can find links to XPI files ending an-fx.xpi but downloading these and picking the install-from-file route doesn't seem to work. (The plugin installs but doesn't work.) I'm thinking maybe they're for Firefox for Android?

How can I make sure I'm accessing XPIs for the GNU/Linux desktop?

Answer 1

The simplest solution would be to change the User-Agent string that identifies your browser to one that the store will accept as bona-fide Firefox.

To override this string :

1. Type about:config into Firefox’s address bar and press Enter
2. Type general.useragent.overridepreference in the search box, and if it exists go to step 4 (double-click it)
3. Right-click on the about:config page, point to New, and select String
4. Name the preference general.useragent.override
5. Enter your desired user agent as the value of the preference.

A searchable database of user-agent strings can be found in myip.ms, where you can search for one that suits you.

Another (tiring) solution would be to google for the addon and then download the xpi file.