public async Task <IActionResult> DisableMfa(DisableMfaViewModel disableMfaViewModel)
        {
            if (ModelState.IsValid)
            {
                if (disableMfaViewModel.Confirmation)
                {
                    var user = await _userManager.GetUserAsync(User);

                    if (user == null)
                    {
                        throw new InvalidOperationException();
                    }
                    var result = await _userManager.SetTwoFactorEnabledAsync(user, false);

                    return(RedirectToAction("Index"));
                }
            }
            ModelState.AddModelError(string.Empty, "invalid operation.");
            return(View(disableMfaViewModel));
        }
        public IActionResult DisableMfa()
        {
            var disableMfaViewModel = new DisableMfaViewModel();

            return(View(disableMfaViewModel));
        }