[gruez]

Are you talking about a prompt like this[1]? If so, there should be a poorly named "more options" or "don't have your phone?" link that gives you the option to enter your TOTP code instead.

[1] https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh...

[theragra]

I vaguely remember situation where it was not possible for me to choose such option, but I don't remember details