Update Startup.cs

Author: HaoK

src/ProjectTemplates/Web.ProjectTemplates/content/RazorPagesWeb-CSharp/Startup.cs

@@ -69,7 +69,7 @@ public void ConfigureServices(IServiceCollection services)
                 options.UseSqlite(
                     Configuration.GetConnectionString("DefaultConnection")));
 #endif
-            services.AddDefaultIdentity<IdentityUser>()
+            services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
                 .AddDefaultUI(UIFramework.Bootstrap4)
                 .AddEntityFrameworkStores<ApplicationDbContext>();