Pega Customer Decision Hub provides two services for registering app users with the system. Push notifications (from actions) are only sent to registered customers. It is the responsibility of the app developer to code the app to invoke these services, at appropriate points in time. For example, when a customer installs the app, the app must register with the platform push notification service (e.g. APNs, FCM) and should then invoke the marketing registration service.
Pega Customer Decision Hub