Verification at login
When you log in from an unusual location or there is some suspicion that you may be a robot based on your actions, then Yandex may flag your login attempt. In this case Yandex will ask you to enter a CAPTCHA or the contact information you linked to your account (like your phone number or email address). Hackers that don't know what email address or phone number you linked will not be able to log in to your account, but Yandex always sends you a notification every time there is a suspicious login attempt.
You won't need to get a confirmation code in order to verify your account; just correctly enter your masked phone number or email address in its entirety. For example:
The Use another confirmation method button lets you verify using an email address instead of your phone number (if you confirmed an alternate email address).
If you can't correctly enter the contact information that's masked in the form or restore access to your account, please contact Support.