In order to use the Apple Push Notification functionality, you need to have an Apple Entitlement certificate which is stated in the APN profile. The APN profile is loaded when you start a workflow that depends on it. Changes to the profile become effective when you restart the workflow.

Configuration

To create a new APN profile configuration, click the  New Configuration  button in the upper left part of the Desktop window, and then select  APN Profile from the menu.

...