Setting up Two-Factor Authentication (2FA) has been implemented as a mandatory authentication process to ensure the security of our clients' accounts. 

To be able to change the Two-Factor authentication method you are using, you need to first deactivate the current method you are using, then enable the other authentication option on the other device you want to use. 

To disable Two-Factor Authentication via Email you need to go to Settings and tap the toggle near Enable 2FA via Email