A clear, concise guide on using a hardware Security Key1 with a Gmail account. I didn’t even know it was possible to avoid using SMS as your backup second factor – thanks to this guide I have my Key as my main and the Authenticator app as backup. No SMS involved. (My phone number has since been removed from my Google account)
The official documentation/setup guide should really make this clearer.
External link: How To Add A Security Key To Your Gmail (Tech Solidarity)