private async Task <bool> IsSent(SendSmsCommand command)
        {
            var notificationReference = command.Message.Conversation.ConversationId;

            var notificationList = await _notificationClient.GetNotifications("sms", string.Empty, notificationReference);

            var lastNotification = notificationList.notifications
                                   .OrderByDescending(n => n.createdAt)
                                   .FirstOrDefault();

            return(lastNotification == null || lastNotification.status == "delivered");
        }