When you enable multi-factor authentication on your email marketing platform, you are typically asked to set up a primary method of authentication, such as an authenticator app or SMS verification. During this setup, you are also given a set of backup codes. These codes are single-use and can be stored securely (e.g., in a password manager or written down and kept in a safe place). If you ever lose access to your primary authentication method, you can use one of these backup codes to log in.