Step 1:Add get package to pubspec.yaml file:

                        get: 
                      

Step 2: Import get package in main.dart file

                      import 'package:get/get.dart';
                      

Step 3: code

For creating an app, use GetMaterialApp instead of MaterialApp because we are using GetX library.

                        import 'package:flutter/material.dart';
                        import 'package:get/get.dart';

                        void main() {
                          runApp(MyApp());
                        }

                        class MyApp extends StatelessWidget {
                          
                            // This widget is the root of your application.
                            @override
                            Widget build(BuildContext context) {
                              return GetMaterialApp(
                              title: 'Scaffold demo',
                              theme: ThemeData(
                                
                                primarySwatch: Colors.blue,
                              ),
                              home: MyHomePage(),
                              debugShowCheckedModeBanner: false,
                              );
                            }
                        }

                        class MyHomePage extends StatelessWidget {
                        @override
                        Widget build(BuildContext context) {
                          return Scaffold(
                          appBar: AppBar(
                            title: Text('GeeksforGeeks Scaffold'),
                            centerTitle: true,
                            backgroundColor: Colors.green,
                          ),
                          body: Center(
                            child: ElevatedButton(
                            child: Text('Open Snackbar'),
                            onPressed: (){
                             
                            },
                            ),
                          ),
                          );
                        }
                        }


                        

create Snackbar using Get.snackbar(title, message);

                      Get.snackbar(
                              "GeeksforGeeks",
                              "Hello everyone",
                              icon: Icon(Icons.person, color: Colors.white),
                              snackPosition: SnackPosition.BOTTOM,
                                
                              );
                      

Complete code

                      import 'package:flutter/material.dart';
import 'package:get/get.dart';

void main() {
runApp(MyApp());
}

class MyApp extends StatelessWidget {
	
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
	return GetMaterialApp(
	title: 'Scaffold demo',
	theme: ThemeData(
		
		primarySwatch: Colors.blue,
	),
	home: MyHomePage(),
	debugShowCheckedModeBanner: false,
	);
}
}

class MyHomePage extends StatelessWidget {
@override
Widget build(BuildContext context) {
	return Scaffold(
	appBar: AppBar(
		title: Text('GeeksforGeeks Scaffold'),
		centerTitle: true,
		backgroundColor: Colors.green,
	),
	body: Center(
		child: ElevatedButton(
		child: Text('Open Snackbar'),
		onPressed: (){
			Get.snackbar(
			"GeeksforGeeks",
			"Hello everyone",
			icon: Icon(Icons.person, color: Colors.white),
			snackPosition: SnackPosition.BOTTOM,
				
			);
		},
		),
	),
	);
}
}

Some additional parameters

   Get.snackbar(
              "GeeksforGeeks",
               "Hello everyone",
               icon: Icon(Icons.person, color: Colors.white),
               snackPosition: SnackPosition.BOTTOM,
               backgroundColor: Colors.green,
               borderRadius: 20,
               margin: EdgeInsets.all(15),
               colorText: Colors.white,
               duration: Duration(seconds: 4),
               isDismissible: true,
               dismissDirection: SnackDismissDirection.HORIZONTAL,
               forwardAnimationCurve: Curves.easeOutBack,

    );