Hi Spark Page users,
We’re actively investigating this issue for our Product Roadmap. We will update you as to the status soon.
Spark Page Product ManagerAnonymous commented
A temporary fix. I have purchased domains from GoDaddy and applied them to the Adobe URL. Select "With Masking" and it hides the Adobe URL. It looks and works fine until you add it to Social Media (FB) It doesn't create a Pretty URL with image. Just the URL text. You can create subdomains from the purchased Domain.