Добавил форму выхода (Logout)

webinar65/Controllers/AccountController.cs

@@ -45,5 +45,15 @@ namespace webinar65.Controllers
 
             return View(model);
         }
+
+        public async Task<IActionResult> Logout()
+        {
+            if (_signInManager.IsSignedIn(User))
+            {
+                await _signInManager.SignOutAsync();
+            }
+
+            return RedirectToAction("Login");
+        }
     }
 }

webinar65/Views/Shared/_Layout.cshtml

@@ -35,6 +35,10 @@
                     <li><a asp-area="" asp-controller="Home" asp-action="Index">Home</a></li>
                     <li><a asp-area="" asp-controller="Home" asp-action="About">About</a></li>
                     <li><a asp-area="" asp-controller="Home" asp-action="Contact">Contact</a></li>
+                    @if (User.Identity.IsAuthenticated)
+                    {
+                        <li><a asp-area="" asp-controller="Account" asp-action="Logout">Log out</a></li>
+                    }
                 </ul>
             </div>
         </div>