I have been accepted to participate in the beta version, and I gotta say this works very well.
There are some minor details that could be improved, but really nothing that ruins the experience. Really great product. Also check out their other services; You will not be dissapointed.

Magnus
Denmark

Excellent add-on and it works as intended, also works on mobile as well. Loving it so far, keep up the great work Proton.

Beautifull, Fast, good feature, so far so good...

So far, it doesn't work on most websites. I mean, it doesn't show the Proton Pass icon and don't autofill.

Great addition. While it is at experimental level, I am enjoying the basic functionalities. Keep up the great work!

This add-on is totally not web development friendly. If for some reason you choose not to offer user+password remembering functionalities on localhost / non encrypted connections, you should be decent enough to fallback your user to default Firefox functionalities.

Addon not working in the Mullvad browser. (file appears to be corrupt error) I know, the service is on beta and this is a browser that uses firefox "framework" and is not necessarily Firefox. However I'd like the service to at least be accessible from web address (to consider adopting the service). I am not installing Firefox instead, as it would kill the entire purpose of a privacy-focused environment.