How to create custom snackbar which has gradient background color in Flutter?

I am building an application using Flutter, and I am using Firebase as an backend. Suddenly, I need to use snackbar to show the user message about authentication. For example: user-not-found, password or email is wrong. Then I used default snackbar, it worked pretty well, but I wanted it to be appealing on the eye. So eye created custom snackbar, needless to say I used chatgpt for some parts. Here is how you can create custom snackbar with the gradient background color.

import 'package:flutter/material.dart';

class CustomGradientSnackbar {
   final String text;
   final Gradient gradient;
   final Color textColor;

   CustomGradientSnackbar({
    required this.text,
    required this.gradient,
    required this.textColor,
  });

  void show(BuildContext context) {
    OverlayState? overlayState = Overlay.of(context);
    OverlayEntry overlayEntry;

    overlayEntry = OverlayEntry(
      builder: (BuildContext context) => Positioned(
        bottom: 0,
        left: 0,
        right: 0,
        child: Material(
          elevation: 6.0,
          child: Container(
            padding:
                const EdgeInsets.symmetric(horizontal: 16.0, vertical: 10.0),
            decoration: BoxDecoration(
             gradient: gradient,
            ),
            child: Text(
              text,
              style: TextStyle(
                color: textColor,
                fontWeight: FontWeight.bold,
              ),
            ),
          ),
        ),
      ),
    );

    overlayState.insert(overlayEntry);

    Future.delayed(const Duration(seconds: 2)).then((_) {
      overlayEntry.remove();
    });
  }
}

Result:

If anyone knows better way of creating custom gradient snackbar, feel free to answer.

ElevatedButton(
          onPressed: () {
            Flushbar(
              // title: "User not found",
              // message: 'User not found.',
              messageText: const Text(
                'User not found',
                style: TextStyle(
                    color: Colors.white,
                    fontSize: 16,
                    fontWeight: FontWeight.w500),
              ),
              duration: const Duration(seconds: 3),
              backgroundGradient: const LinearGradient(colors: [
                Color(0xffD95F30),
                Color.fromRGBO(181, 120, 44, 1),
                Color.fromRGBO(167, 149, 48, 1)
              ]), //here's the gradient support

            ).show(context);
          },
          child: const Text('click'))