I have logged into G-Wizard in the past
Is there a typo in the email you entered?
We need you to type in the email you used for your free trial or subscription. It's easy to accidentally get a typo of some kind. You can check it on the login popup:
You can see the email you entered at the top, near the red arrow. To change it, click the Email button at the bottom right.
Did this fix the problem?