Telegram can dictate the login code in an automated phone call, but only for accounts that have two-step verification switched on. This is a deliberate restriction, not an availability problem.
Turning it on
- While signed in, open Settings.
- Go to Privacy and Security.
- Choose Two-Step Verification and set a password.
- Add a recovery email when prompted. Without one, a forgotten password cannot be reset.
From then on, the login screen offers a call as an alternative after the SMS attempt.
Why it is restricted this way
A dictated code is easier for an attacker to obtain than a text: a call can be answered by whoever is holding the handset, and voice delivery is more exposed to interception and redirection. Requiring a second factor means the code alone is not enough to take the account, which is what makes offering the call safe at all.
Mobile numbers only
Telegram accounts can only be attached to a mobile number. Landlines are not supported, so a landline will not receive a code by either method.
Updated