using System;

using System.Collections.Generic;

using System.Threading.Tasks;

using FirebaseAdmin.Messaging;

using Google.Apis.Auth.OAuth2;

using FirebaseAdmin;

public class Program

{

    public static async void Main()

    {

            await SendMulticastAsync();

            Console.WriteLine("");

    }

    internal static async Task SendMulticastAsync()

        {

            // [START send_multicast]

            // Create a list containing up to 500 registration tokens.

            // These registration tokens come from the client FCM SDKs.

            var registrationTokens = new List<string>()

            {

                "dznJBtBvQkB0t8W2TKxvI2:APA91bGdGJSeciJF23EIZwrvjtYIIdNc5HxxyZvowa_TDccknXmLOmGzfd_NKZSLsp0j3V9AqoR3cOvIVDCZMdtNY6XyWGdkgcGK90Te02urrlmUKsVCssZE3rMtHGbrZD4VUTjuKGcS",

                "dznJBtBvQkB0t8W2TKxvI2:APA91bGdGJSeciJF23EIZwrvjtYIIdNc5HxxyZvowa_TDccknXmLOmGzfd_NKZSLsp0j3V9AqoR3cOvIVDCZMdtNY6XyWGdkgcGK90Te02urrlmUKsVCssZE3rMtHGbrZD4VUTjuKGcS",

            };

            var message = new MulticastMessage()

            {

                Tokens = registrationTokens,

                Data = new Dictionary<string, string>()

                {

                    { "score", "850" },

                    { "time", "2:45" },

                },

            };

            FirebaseApp.Create(new AppOptions()

            {

                Credential = GoogleCredential.FromFile("path/to/what/you/downlowded.json"),

            });

​

            var response = await FirebaseMessaging.DefaultInstance.SendMulticastAsync(message);

            // See the BatchResponse reference documentation

            // for the contents of response.

            //Console.WriteLine($"{response.SuccessCount} messages were sent successfully");

            Console.WriteLine(response);

            // [END send_multicast]

        }

}