We can configure the SCA site to redirect unauthenticated visitors to a login page with a link to a registration form. In SCA, we have a default feature to restrict our entire site to logged in users only.
Go to Commerce > Websites > Website List
Click Edit next to the website to which we want to restrict access.
Check the Password-protect Entire Site box under shopping tab
Set the Customer Registration Is field to one of the following:
- required
- existing customers only
