I'm new to iOS programming.I'm trying to write an app for screen broadcasting/recording.Follow the guide of WWDC2018.1. new target of "Broadcast Upload Extension" and "Broadcast Setup UI Extension".Note: neither SampleHandler.swift nor BroadcastSetupViewController.swift is modified.2. modify the ViewController.swift as followingimport UIKit import ReplayKit @available(iOS 12.0, *) class ViewController: UIViewController { var broadcastPicker: RPSystemBroadcastPickerView? var broadcastPicker: RPSystemBroadcastPickerView? override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view. let broadcastPicker = RPSystemBroadcastPickerView(frame: CGRect(x: 0, y: 0, width: view.bounds.width, height: 500)) broadcastPicker.preferredExtension = "com.myapp.extension" view.addSubview(broadcastPicker) } }After installation, when pressing the app to start broadcasting, following screen is shown. There is no icon of my app. The preferredExtension is confirmed correct as the extension's Bundle Identifier.https://i.stack.imgur.com/vFotKl.jpgIf starting broadcast from the system, there are many provider options, but not my app.https://i.stack.imgur.com/qilOLl.jpgPlease help. Thank you.