You can disable the username/password login option by navigating to the Service Management Portal on our website, opening Settings - Login methods and disabling the Email and Password section. For a quick demonstration on where to find this setting, please take a look at our video guide.
Please note that you must have at least one alternative login method in order to disable the username/password option.
Note: In case you have any questions or are experiencing any issues, please feel free to contact our 24/7 customer support team.