How to add an image over top of the dialog in a Flutter?

I am trying to design my dialog like in the picture below.

However, I can't seem to wrap my head around how to do it. Because I am new started in Flutter.

Below is my code:

showDialog(
    barrierDismissible: false,
    context: context,
    builder: (BuildContext context) {
      return Dialog(
        shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(10.0)), //this right here
        child: Wrap(
          children: [
            Container(
              child: Padding(
                padding: const EdgeInsets.only(
                  right: 16,
                  left: 16,
                  top: 32,
                  bottom: 16,
                ),
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: [
                    Lottie.asset(
                      "assets/animations/no_connection.json",
                      height: 180,
                    ),
                    SizedBox(
                      height: 8,
                    ),
                    CustomText(
                      "description",
                      fontWeight: FontWeight.bold,
                      fontSize: 14,
                    ),
                    SizedBox(
                      height: 32,
                    ),
                    Row(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        SizedBox(
                          width: 120.0,
                          child: ElevatedButton(
                            style: ButtonStyle(
                              backgroundColor:
                              MaterialStateProperty.all(kOrange),
                            ),
                            onPressed: () async {
                              getData();
                              getVipStatus();
                              Navigator.of(context).pop();
                            },
                            child: FittedBox(
                              fit: BoxFit.fitWidth,
                              child: CustomText(
                                "try",
                                color: Colors.black,
                              ),
                            ),
                          ),
                        ),
                      ],
                    ),
                  ],
                ),
              ),
            ),
          ],
        ),
      );
    });

I am a beginner in Flutter programming language, I used to work with Java. I put my code in the description section and I try to use the photo inside the frame, the photo will move to the top of the frame. I have shown an example of it in the description section.

You can follow this snippet

showDialog(
    context: context,
    builder: (context) {
      final size = MediaQuery.of(context).size;
      return Center(
        child: Dialog(
            backgroundColor: Colors.transparent, //must have
            elevation: 0,
            child: SizedBox(
              height: size.height * .6,
              child: Stack(
                children: [
                  Positioned(
                      top: (size.height * .2) / 2,
                      child: Container(
                        height: size.height * .5,
                        width: size.width * .9,
                        color: Colors.red,
                      )),
                  Align(
                    alignment: Alignment.topCenter,
                    child: Container(
                      height: size.height * .2,
                      width: size.height * .2,
                      decoration: ShapeDecoration(
                        shape: CircleBorder(),
                        color: Colors.yellow,
                      ),
                    ),
                  ),
                ],
              ),
            )),
      );
    },
  );

It will provide like below, play with the value