Stuck at registration page "This webinar is for users with a Zoom account" I already have a Zoom Acc

Welcome to the Zoom Community, @PatrickGoo 

Make sure you are logged into your Zoom account on the Web Portal at https://zoom.us before attempting to register. 

How to manage Registration Settings
Sign in to the Zoom web portal.
In the navigation menu, click Webinars.
Click the topic of the webinar that you want to customize.
Scroll down to the Invitations tab.
In the Registration Settings section, click Edit on the right side. The Registration window will appear.

Regards,

Diana