Players are required to enter a two-factor authentication (2FA) code from a supported Authenticator app each time they log in to Call of Duty®: Warzone™ Mobile with an Activision account. Backup codes will not work when logging in to the game.
Please refer to the following tips if you’re having issues with 2FA when logging in to Warzone™ Mobile.
Please also refer to Using Two-Factor Authentication (2FA) with an Activision Account for more information.