Echo.cs

using System;
using System.Threading.Tasks;
using RxTelegram.Bot.Interface.BaseTypes.Requests.Messages;

namespace RxTelegram.Bot.Examples.Echo;

public static class Echo
{
    private const string BotToken = "<PASTE YOUR BOT TOKEN HERE>";

    public static async Task Main()
    {
        var bot = new TelegramBot($"{BotToken}");
        var me = await bot.GetMe();
        Console.WriteLine($"Bot name: @{me.Username}");

        var subscription = bot.Updates.Message.Subscribe(x =>
            {
                bot.SendMessage(new SendMessage
                {
                    ChatId = x.Chat.Id,
                    Text = x.Text
                });
            },
            exception => Console.WriteLine($"An error has occured: {exception.Message}"));
        Console.ReadLine();
        subscription.Dispose();
    }
}