Hm, the point of authenticator is to not use the phone, because phjone numbers may be more vulnerable. wasn't there a case of social hacking where the telco forwarded to hacker's phone?
That was a case of them circumventing the 2FA he had, they just granted access.
Authenticator is a mobile phone app, how are you supposed not to use your phone with it?
* or a backup phone number that's been verified (i.e. send a verification code and confirmed).