It works. To scan, you have to click and drag a box around the qr code

I import my QR code, it says it worked correctly and it starts showing me random codes that aren't the ones on my phone and don't work

It was not so easy to use. There is a button that looks like it helps to scan a QR code, but it does nothing. So I clicked on the pencil icon, then imported the QR code, and it worked, but the extension only mentioned that some QR codes would work. The one that I use, a very popular one, was not mentioned. However, I tried and it is showing the proper codes now.

Sadly it does not work with some major authenticators (eg microsoft).
When it works it's nice - tried it with Octa.
When it does not work it's very confusing, as it won't give you an indication of what's happening. The interface is very basic, can't really tell what's what, how to start. Weird icons instead of simple textual buttons is a rubbish modern fad.

Completely broken and useless. No icon appears in the navigation bar.

This add-on has been a godsend for me setting up 2FA on various sites. Unfortunately as of today the "Scan QR Code" button is doing nothing, and I can't add additional sites to the authenticator app. Not sure why this is failing at the moment. It would be great if the developer could look at this issue.