Oh yea.. if you wanna show the error against the email input box, then instead of following the override method, you can add a custom validator for the email field: https://supertokens.io/docs/emailpassword/common-customizations/signup-form/field-validators
which checks if the email is the one allowed to sign up or not. If it isn't you can return an error string, and that would be shown on the frontend UI