I forgot my username or email address
You can attempt to remember your username on your own:
Go to the Access Management page. If you accessed your account recently from the computer or browser you're currently using, you'll see a username suggestion appear under the Username or email field.
If you know the phone number linked to your account along with your first and last name as entered in Yandex.Passport, then open the Restore username page. Make sure that the username you're looking for is not one of the suggestions on the page, click Username is not in the list, and enter your number. Yandex will send you an SMS with a confirmation code that you will have to enter on the next page.
Then you will have to enter your first and last name as they appear in your account. If an account with that phone number and name is found, Yandex.Passport will display it in the list. If it isn't found, see if you can remember your username some other way.
If you used this address to communicate with your friends, family or colleagues, try to contact them, for example, through social networks. Maybe they will remember your address or find a message from you in their inboxes and can tell what address it was sent from.
Support can locate your username if you can remember other details about your account:
If you remember your username, but have forgotten your password or, when you try to log in to your account, you get the message “Wrong username/password! Login failed”, please follow our recommendations.