The Help Center is not accessible if a user is not yet logged in. All the user can see is the login page when accessing https://mydomain.atlassian.net/servicedesk/customer/portals
On https://support.atlassian.com , there is a customised version where the Help Center is accessible without logging in: https://support.atlassian.com/customer/servicedesk-portal
Show the Help Center even for anonymous users. When a user clicks in to create a request, THEN prompt the log-in screen.