If you have previously set up an authenticator app and the login page rejects your number, check you are using the original authenticator app you used to pair with your account.

Alternatively, check that you haven’t paired your app with a different login which may have overridden your existing pairing.

If you are still having difficulty either contact an admin within your organisation with permission to disable 2FA for users or contact support@signstix.com who will reset your account.