setup the ifrst VC in applicationDidFinishLaunching

vcInApplicationDidFinishLaunching.swift

func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
    let window = UIWindow()
    let vc = ViewController()
    vc.view.backgroundColor = .red
    window.rootViewController = vc
    self.window = window

    window.makeKeyAndVisible()

    return true
  }