There is no Edit site in Parallels Presence Builder button under Websites & Domains tab for the subscription.
Subscription has no resource "Sites published with Web Presence Builder" or resource limits were not synced with service template.
Check that subscription has "Sites published with Web Presence Builder" resource and its limit is not reached. To check that go to Operations > Subscriptions > example.com > Resources.
If resource "Sites published with Web Presence Builder" exists under Resource tab, but you still cannot create site, it means that limits were not synced:
Go to Top > Products > Service Templates > "Template Name" click "Apply Template Limits and Parameters" button.
NOTE: This action will be performed for all the subscriptions under this plan.