In flutter how to use GetX to get and set first frame in video player?

I am using video_player with GetX. And as you can see in official example, to get and set first frame of video as thumbnail, you have to use empty setState.

@override
  void initState() {
    super.initState();
    _controller = VideoPlayerController.network(
        'https://flutter.github.io/assets-for-api-docs/assets/videos/bee.mp4')
      ..initialize().then((_) {
        // Ensure the first frame is shown after the video is initialized,
        // even before the play button has been pressed.
        setState(() {});
      });
  }

Now I am not able to understand even that how to figure out below code using GetX. (i.e. how do I get first frame using GetX and set it on video player as thumbnail.)

// Ensure the first frame is shown after the video is initialized, // even before the play button has been pressed. setState(() {});

Any help is much appreciated.

Edit: I am using GetX hence I do not want to use stateful widget. So how can i achieve the same example using GetX, especially what this part is doing - setState(() {});