public IActionResult Login(string username)
        {
            if (string.IsNullOrEmpty(username))
            {
                return(RedirectToAction($"Index", new { validationException = "Please enter a username." }));
            }

            if (!SqlHelper.IsExistingUser(username))
            {
                SqlHelper.AddNewUser();
            }

            return(RedirectToAction("Index", $"Dashboard"));
        }