Section: 5.2.6.12.2 Nnef_APISupportCapability_Subscribe service operation
Content: Service operation name: Nnef_APISupportCapability_Subscribe Description: The AF subscribes to receive notification about the availability or expected level of support of a service API for a UE or a group of UEs. Inputs, Required: UE ID or External Group ID, Report Type (One-time report or Continuous report). Inputs, Optional: Duration of Reporting, callback URI. Outputs, Required: Operation execution result indication. When the subscription is accepted: Subscription Correlation ID, API indication.