As the API is private, customers won't have access to it. Instead, the following steps show how customers can cancel their own subscription from Control Hub:

1. The Partner Admin can navigate to the "Hybrid" Services page on the Customer's Control Hub.

2. Locate the "BroadWorks Calling" card.

3. Once all users have been de-provisioned from Webex for BroadWorks for that Customer, the Partner should see a button to "Clear Configuration" (i.e., delete their customer_config entry in BPB).