appsettings.json

{
    "Bot":{
        "Token":""
    }
    
}

BotHostedService.cs

using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Telegram.Bot;
using Telegram.Bot.Polling;
using Telegram.Bot.Types.Enums;

namespace bot1;

public class BotHostedService(ILogger<BotHostedService> logger,
ITelegramBotClient botClient,
IUpdateHandler updateHandler) : IHostedService
{
    public async Task StartAsync(CancellationToken cancellationToken)
    {
        var me = await botClient.GetMe(cancellationToken);
        logger.LogInformation("{bot} has started successfully.", me.FirstName ?? me.Username);
        botClient.StartReceiving(
            updateHandler, new ReceiverOptions
            {
                DropPendingUpdates = true,
                AllowedUpdates = [UpdateType.Message]
            },

        cancellationToken: cancellationToken);
    }

    public Task StopAsync(CancellationToken cancellationToken)
    {
        logger.LogInformation("{service} id exiting ...", nameof(BotHostedService));
        return Task.CompletedTask;
    }
    
}

BotUpdateHandler.cs

using Microsoft.Extensions.Logging;
using Telegram.Bot;
using Telegram.Bot.Polling;
using Telegram.Bot.Types;

namespace bot1;

public class BotUpdateHandler(ILogger<BotUpdateHandler> logger) : IUpdateHandler
{
    public Task HandleErrorAsync(ITelegramBotClient botClient, Exception exception, HandleErrorSource source, CancellationToken cancellationToken)
    {
        logger.LogError(exception, "something happend wrong {message}", exception.Message);
        return Task.CompletedTask;
    }

    public async Task HandleUpdateAsync(ITelegramBotClient botClient, Update update, CancellationToken cancellationToken)
    {
        logger.LogInformation("new message from {client}", update.Message?.Text);
        if (update.Type is Telegram.Bot.Types.Enums.UpdateType.Message)
        {
            logger.LogInformation("new message from {client} with text: {text}", update.Message?.Chat.Username, update.Message?.Text);

            if (update.Message!.Text!.Trim().ToLower() == "/start")
            {
                await botClient.SendMessage(chatId: update.Message.Chat.Id,
                text: """
                     *📜 Qo'llab-quvvatlanadigan buyruqlar:*

                        - `/fun-emoji seed`
                        - `/avataaars seed`
                        - `/bottts seed`
                        - `/pixel-art seed`

               """,
               parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
            cancellationToken: cancellationToken
               );
            }
            else
            {
                List<string> patterns = ["/fun-emoji", "/avataaars", "/bottts", "/pixel-art"];
                var lst = update.Message.Text?.Split(" ", StringSplitOptions.RemoveEmptyEntries);
                if (lst is null || lst.Length < 1)
                {
                    return;
                }
                string emoji = lst[0].Trim().ToLower();
                string? seed = lst.Length > 1 ? lst[1] : null;
                if (patterns.Contains(emoji) && seed is not null)
                {
                    var url = $"https://api.dicebear.com/8.x{emoji}/png?seed={seed}";
                    await botClient.SendPhoto(
                    chatId: update.Message.Chat.Id,
                    photo: url,
                    cancellationToken: cancellationToken);
                }
                else if (!patterns.Contains(emoji) && seed is not null)
                {
                    await botClient.SendMessage(
                        chatId: update.Message.Chat.Id,
                        text: "❌ Noma'lum buyruq. Quyidagilardan birini ishlating:  \n \n `/fun-emoji`,\n` /bottts`,\n` /avataaars`,\n` /pixel-art`",
                        parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                        cancellationToken: cancellationToken);
                }
                else if (patterns.Contains(emoji) && seed is null)
                {
                    await botClient.SendMessage(
                        chatId: update.Message.Chat.Id,
                        text: $"❌ Iltimos, buyruqdan keyin (seed) kiriting. \n Misol: {emoji} Ali✔️",
                        parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                        cancellationToken: cancellationToken);
                }
                else
                {
                    await botClient.SendMessage(
                    chatId: update.Message.Chat.Id,
                    text: "❌ Iltimos, avatar olish uchun to'g'ri buyruqdan foydalaning.",
                    parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                    cancellationToken: cancellationToken);
                }
            }
        }
        await Task.CompletedTask;
    }
}

launchSettings.json

{
  "profiles": {
    "Local": {
      "commandName": "Project",
      "dotnetRunMessages": true,
      "environmentVariables": {
        "DOTNET_ENVIRONMENT": "Development"
      }
    }
  }
}

program.cs

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Telegram.Bot;
using Telegram.Bot.Polling;
using bot1;

var builder = Host.CreateApplicationBuilder();

builder.Services.AddSingleton<IUpdateHandler, BotUpdateHandler>();

builder.Services.AddSingleton<ITelegramBotClient, TelegramBotClient>(x =>
    new TelegramBotClient(builder.Configuration["Bot:Token"]
        ?? throw new ArgumentException("Telegram Bot Token is not configured.")));

builder.Services.AddHostedService<BotHostedService>();

var app = builder.Build();

app.Run();

secrets.json

{
    "Bot":{
        "Token":"7559344242:AAFzC_rUuDeykKqE4lfx3T_uN9-2v5z4iKU"
    }
    
}