How to implement a Custom dialog box in flutter?

import 'package:flutter/material.dart';
import 'package:vender_app/core/colors.dart';
import 'package:flutter_svg/flutter_svg.dart';
import 'package:flutter_svg_provider/flutter_svg_provider.dart' as fs;
import 'package:vender_app/core/image_constant.dart';

class AlertNoResultFoundDialog extends StatelessWidget {
  const AlertNoResultFoundDialog({
    this.icon,
    this.title,
    this.message,
    this.actions = const [],
    Key? key,
  }) : super(key: key);

  final Widget? icon;
  final String? title;
  final String? message;
  final List<Widget> actions;

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(20.0),
      ),
      icon: icon,
      title: title == null
          ? null
          : Text(
              title!,
              textAlign: TextAlign.center,
            ),
      titleTextStyle: TextStyle(
          color: AppColors.reusltNoFoundTitleColor,//as per your color
          fontSize: 20,
          fontWeight: FontWeight.w700),
      content: message == null
          ? null
          : Text(
              message!,
              textAlign: TextAlign.center,
            ),
      contentTextStyle: TextStyle(
          color: AppColors.reusltNoFoundColor,//as per your color
          fontSize: 18,
          fontWeight: FontWeight.w500),
      actionsAlignment: MainAxisAlignment.center,
      actionsOverflowButtonSpacing: 8.0,
      actions: actions,
    );
  }
}

 showDialog(
                  context: context,
                  builder: (ctx) => AlertNoResultFoundDialog(
                    icon: SizedBox(
                      height: 173,
                      width: 210,
                      child: SvgPicture.asset(
                          "assets/images/no_result_found.svg",
                          fit: BoxFit.scaleDown),
                    ),
                    title: 'No Results Found',
                    message:
                        'Try adjusting your search to find what you are looking for.',
                    actions: [
                      TextButton(
                        onPressed: () => Navigator.of(ctx).pop(),
                        child: Padding(
                          padding: const EdgeInsets.only(top: 20.0),
                          child: GestureDetector(
                            onTap: () {},
                            child: Container(
                              height: 60,
                              width: width * 0.6,
                              decoration: BoxDecoration(
                                gradient: LinearGradient(
                                  colors: [
                                    const Color(0xFF4AB21D),
                                    const Color(0xFF4AB21D),
                                  ],
                                  begin: Alignment.centerLeft,
                                  end: Alignment.centerRight,
                                ),
                                borderRadius: const BorderRadius.all(
                                  Radius.circular(27.5),
                                ),
                              ),
                              child: Center(
                                child: GestureDetector(
                                  onTap: () {
                                   //yur screen
                                  },
                                  child: Text(
                                    'Search Again',
                                    textAlign: TextAlign.left,
                                    style: TextStyle(
                                      color: Color(0xFFFFFFFF), 
                                   
                                  
                                      fontSize: width * 0.05,
                                      fontWeight: FontWeight.w600,
                                      fontFamily: 'ProductSans',
                                    ),
                                  ),
                                ),
                              ),
                            ),
                          ),
                        ),
                      ),
                    ],
                  ),
                );