didReceiveIncomingPushWithPayload completion handler

Hey,

I would like to ask when we should call completion handler for didReceiveIncomingPushWithPayload delegate method if we have some async code fired inside.

Let's have following examples:

(completion called already in same runloop cycle)

private let provider: CXProvider

func pushRegistry(_ registry: PKPushRegistry, didReceiveIncomingPushWith payload: PKPushPayload, for type: PKPushType, completion: @escaping () -> Void) {
    /// code to get call info
    provider.reportNewIncomingCall(with: uuid, update: update) { error in
         /// some code here
    }
    completion()
}

(completion called at "future" when we "finish" handling voip notification, potentially future runloop cycle)

private let provider: CXProvider

func pushRegistry(_ registry: PKPushRegistry, didReceiveIncomingPushWith payload: PKPushPayload, for type: PKPushType, completion: @escaping () -> Void) {
    /// code to get call info
    provider.reportNewIncomingCall(with: uuid, update: update) { error in
         /// some code here
        completion()
    }
}

(error cases in both examples were omitted but i'm aware I should handle them too)

Which one is more correct?