Apparently wrong Udev rules are provided on the site, sorry for that. Please download and use file from firmware home site: 70-u2f.rules. After the download you could use this simple installation script: install_rules.sh. Example run using terminal:
# please input your password when asked
If it will not work immediately after running that, please reboot your OS and try again accessing the device in a browser. Here is a simple test site: https://u2f.bin.coffee/.
Guide regarding setting the Firefox looks fine.
If that fails, here are simple hardware checks:
- Could you tell, is the device showing up? E.g. via the terminal command:
$ lsusb -d 20a0:4287
Bus 003 Device 015: ID 20a0:4287 Clay Logic
- Device should blink once, just after the insertion. Could you confirm the same behaviour on your hardware?
If it will still not work, I will provide further instructions, which would involve execution of a Python tool. I am almost sure though the wrong Udev rules are the cause in this case.
@nitroalex Could you correct the documentation please, specifically the Udev rules file? Perhaps you could reuse my reply regarding automatic rules installation on Ubuntu-like OSes.