You can set up 2FA through one of the other options first. After that, TOTP should be available as an option as well. After setting TOTP up, you can remove the other one.

They're probably hiding the TOTP option because the backup story for Google Authenticator is really poor. If you lose your device, you lose access to all of the accounts you had set up 2FA for with Google Authenticator. Of course, there are other TOTP apps that are better in this regard, but Google is unlikely to promote those because then they'd lose some control over the authentication flow.

I dislike how the only way to get TOTP codes off a device is by rooting. I had a half dozen codes that I had to dump from the sqlite db when I first used authenticator.

I use andOTP[1] installed via f-droid. You can easily get a backup file with your codes.

[1] https://github.com/andOTP/andOTP