public async Task <IActionResult> SignIn(SignInModel model)
        {
            if (ModelState.IsValid)
            {
                // Validate the credentislas
                bool validCredentials = await _accountRepository.ValidateCredentials(model.Username, model.Password);

                if (validCredentials)
                {
                    // Sign-in the user account
                    await HttpContext.SignInAsync(_accountRepository.CreateClaimPrincipal(model.Username));

                    // Redirect to the default page or redirect URL
                    if (string.IsNullOrWhiteSpace(model.Redirect))
                    {
                        return(RedirectToAction("Index", "Admin"));
                    }
                    else
                    {
                        return(LocalRedirect(model.Redirect));
                    }
                }
                else
                {
                    // Invalid credentials, set model error
                    ModelState.AddModelError(nameof(SignInModel.Password), "Invalid credentials");

                    return(View(model));
                }
            }
            else
            {
                // Invalid model state
                return(View(model));
            }
        }