public IActionResult Index()
        {
            TempData["isUpdate"] = false.ToString();
            if (_session != null && _session.GetString("UserModel") != null)
            {
                UserModel     userModel     = JsonConvert.DeserializeObject <UserModel>(_session.GetString("UserModel"));
                UserViewModel userViewModel = new UserViewModel();
                if (userModel == null)
                {
                    return(Redirect("/home/index"));
                }
                userViewModel.userModel = userModel;
                var challenges = _challenge.GetChallengesByLevelIdAsync(userModel.LevelId);
                userViewModel.ChallengeTitle = _challenge.GetChallengesByLevelIdAsync(userModel.LevelId).Select(x =>
                                                                                                                x.ChallengeTitle
                                                                                                                ).ToList();

                return(View(userViewModel));
            }
            else
            {
                return(Redirect("/home/index"));
            }
        }