Unable to install add-ons from addons.mozilla.org

On a fresh install of LibreWolf from Flathub, I was unable to install any extensions from addons.mozilla.org as the browser wasn't being recognized as Firefox, resulting in the following message:

You'll need Firefox to use this extension

Workaround:

Set general.useragent.compatMode.firefox to true and refresh the webpage. The "Add to Firefox" button should appear.

• Tested on Debian Sid (June 2022) and EndeavourOS Artemis (Arch Linux)