Issue
You have added a new domain to your Acquia Cloud application and want it to use your existing Platform CDN entitlement.
Resolution
In case that your application has already been provisioned for Platform CDN and you are now going to be adding a new domain (which was not included in the initial provisioning) - and you want it to utilise the Platform CDN, please file a ticket with Acquia Support. Until this has been provisioned, the new domain will not be able to use the Platform CDN.