chromecast – Methods to entry buttons from the ExpandedMediaController after customizing MiniMediaController in iOS?

I’ve already managed to customise the MiniMediaController like so :

     if let windowScene = scene as? UIWindowScene {
     let storyboard = UIStoryboard(title: "Major", bundle: nil)
     var vc : UIViewController = storyboard.instantiateViewController(withIdentifier: "RootView")
     
     let castContainerVC = GCKCastContext.sharedInstance().createCastContainerController(for: vc)
     castContainerVC.miniMediaControlsItemEnabled = true
     
     let customButton = UIButton(sort: .customized)
     let playImage = UIImage(systemName: "play.fill")
     customButton.setImage(playImage, for: .regular)
     customButton.backgroundColor = .orange
     
     castContainerVC.miniMediaControlsViewController?.setButtonType(.customized, at: 0)
     castContainerVC.miniMediaControlsViewController?.setCustomButton(customButton, at: 0)
     castContainerVC.miniMediaControlsViewController?.setButtonType(.playPauseToggle, at: 1)
     castContainerVC.miniMediaControlsViewController?.setButtonType(.skipNext, at: 2)
              
     self.window = UIWindow(windowScene: windowScene)
     self.window?.rootViewController = castContainerVC
     self.window?.makeKeyAndVisible()
  }

however how can I entry the ExpandedMediaController, if even potential? I’d like to customise it in the identical method I’ve already achieved with the miniplayer.