Configure APEX/Root domains with the B2C Commerce platform's eCDN

APEX/Root aliasing is not supported on the B2C Commerce platform's embedded CDN (eCDN). In addition, custom hostname verification of a APEX/Root domain (i.e. example.com) cannot be completed via eCDN. You must set up a redirect from your root/apex domain to a subdomain such as www.example.com with your DNS provider / redirect service. Forward both HTTP and HTTPS traffic to your custom hostname of the subdomain(i.e. www.example.com). An alternative approach that could allow this would be to stack a third party CDN that allows APEX/Root aliasing on top of eCDN as described in Configure an External CDN or Third-Party Proxy.

What can I do in order to migrate to a proxy zone?
In order to move to a proxy zone as outlined in Migrate a Legacy Zone to a Proxy Zone, it is required to redirect traffic for your APEX/Root domain to a subdomain as mentioned above.