If you want to change your MFA authenticator from an old phone, to a new phone, follow this process.
Log in using your the MFA on your old phone at either https://login.avatarcloud.net:8889/ or the "User Account Management" button on the gateway login page.
Click on the "Enrollment" tab. Click on the edit icon for your authenticator.
Click on the "Change Phone" button.
Follow the displayed instructions for setting up your new phone.
Your old phone should no longer work for MFA at this point and all MFA codes should be generated using your new phone.