public async Task <SubscriberDto> CreateAsync(Subscriber subscriber)
        {
            User user = null;

            if (subscriber.TelegramChatId.HasValue && subscriber.TelegramUserId.HasValue)
            {
                user = await telegramClient.GetUserAsync(subscriber.TelegramChatId.Value, subscriber.TelegramUserId.Value);
            }

            return(new SubscriberDto
            {
                Id = subscriber.Id,
                SendTelegramMessages = subscriber.SendTelegramMessages,
                TelegramChatId = subscriber.TelegramChatId.Value,
                TelegramUsername = subscriber.TelegramUsername,
                NotificationTrigger = subscriber.NotificationTrigger.Serialize(),
                FirstName = user?.FirstName,
                LastName = user?.LastName,
                IsBot = user?.IsBot,
                TelegramUserId = user?.UserId
            });
        }