It works on our Apple Silicon macs.

Have you tried contacting the help desk? https://eid.belgium.be/nl/contact ; they will be happy to help you out.

If there is a "Remove" button, that means the add-on is already installed. It may however be disabled. Please press ctrl+shift+a to go to the add-ons settings in Firefox, and check that the add-on is enabled there. If it is, then everything should just work?

It does work for us (and I use it on Linux on a daily basis).

For support, please contact the BOSA servicedesk via https://eid.belgium.be/fr/contact

For support, please contact the BOSA servicedesk via https://eid.belgium.be/nl/contact

This is because Ubuntu 22.04 LTS ships all browsers using the "snap" system, which doesn't work with the eID, as explained on https://eid.belgium.be/en/faq/why-it-not-possible-use-eid-software-snap-andor-flatpak#7636

The solution is simple: use a browser that is not shipped using snap. The above FAQ entry gives a few download links to browser versions that will work.