SMS has been removed from the GitHub.com sudo page

The option to use SMS on the sudo page on GitHub.com has been removed. Users can still use other 2FA methods as well as their password to pass the sudo check and take sensitive actions. If your account only has SMS as its 2FA method, you can visit your security settings to enable additional methods such as security keys and TOTP, as well as installing the GitHub Mobile app.

To learn more about the GitHub.com sudo prompt, see "Sudo mode". For details about setting up additional 2FA methods, see "Configuring two-factor authentication".