npm install @microsoft/signalr --save

    public class ApplicationSignInManager :
        SignInManager<User>,
        IApplicationSignInManager
    {
   // ...

        public ApplicationSignInManager(
            IApplicationUserManager userManager,
            IHttpContextAccessor contextAccessor,
            IUserClaimsPrincipalFactory<User> claimsFactory,
            IOptions<IdentityOptions> optionsAccessor,
            ILogger<ApplicationSignInManager> logger,
            IAuthenticationSchemeProvider schemes,
            IUserConfirmation<User> confirmation)
            : base((UserManager<User>)userManager, contextAccessor, claimsFactory, optionsAccessor, logger, schemes, confirmation)
        {

    public class ApplicationUserManager :
        UserManager<User>,
        IApplicationUserManager
    {
   // ...

        public ApplicationUserManager(
            IApplicationUserStore store,
            IOptions<IdentityOptions> optionsAccessor,
            IPasswordHasher<User> passwordHasher,
            IEnumerable<IUserValidator<User>> userValidators,
            IEnumerable<IPasswordValidator<User>> passwordValidators,
            ILookupNormalizer keyNormalizer,
            IdentityErrorDescriber errors,
            IServiceProvider services,
            ILogger<ApplicationUserManager> logger,
            IHttpContextAccessor contextAccessor,
            IUnitOfWork uow,
            IUsedPasswordsService usedPasswordsService)
            : base(
                (UserStore<User, Role, ApplicationDbContext, int, UserClaim, UserRole, UserLogin, UserToken, RoleClaim>)store,
                  optionsAccessor, passwordHasher, userValidators, passwordValidators, keyNormalizer, errors, services, logger)
        {

    public class ConfirmEmailDataProtectorTokenProvider<TUser> : DataProtectorTokenProvider<TUser> where TUser : class
    {
        public ConfirmEmailDataProtectorTokenProvider(
            IDataProtectionProvider dataProtectionProvider,
            IOptions<ConfirmEmailDataProtectionTokenProviderOptions> options,
            ILogger<DataProtectorTokenProvider<TUser>> logger)
            : base(dataProtectionProvider, options, logger)
        {

    public class CustomSecurityStampValidator : SecurityStampValidator<User>
    {
   // ...
   
        public CustomSecurityStampValidator(
            IOptions<SecurityStampValidatorOptions> options,
            IApplicationSignInManager signInManager,
            ISystemClock clock,
            ISiteStatService siteStatService,
            ILoggerFactory logger)
            : base(options, (SignInManager<User>)signInManager, clock, logger)
        {

    public interface ILookupNormalizer
    {
        string Normalize(string key);
    }

    public interface ILookupNormalizer
    {
        string NormalizeEmail(string email);
        string NormalizeName(string name);
    }

context.Resource is AuthorizationFilterContext mvcContext

protected override async Task HandleRequirementAsync(
   AuthorizationHandlerContext context,
   DynamicPermissionRequirement requirement)
{
    if (!(context.Resource is AuthorizationFilterContext mvcContext))
    {
      return;
    }

    var actionDescriptor = mvcContext.ActionDescriptor;
    actionDescriptor.RouteValues.TryGetValue("area", out var areaName);
    var area = string.IsNullOrWhiteSpace(areaName) ? string.Empty : areaName;

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;

namespace ASPNETCoreIdentitySample.Services.Identity
{
    public class DynamicPermissionsAuthorizationHandler : AuthorizationHandler<DynamicPermissionRequirement>
    {
        private readonly IHttpContextAccessor _httpContextAccessor;

        public DynamicPermissionsAuthorizationHandler(IHttpContextAccessor httpContextAccessor)
        {
            _httpContextAccessor = httpContextAccessor ?? throw new ArgumentNullException(nameof(httpContextAccessor));
        }

        protected override async Task HandleRequirementAsync(
             AuthorizationHandlerContext context,
             DynamicPermissionRequirement requirement)
        {
            var routeData = _httpContextAccessor.HttpContext.GetRouteData();

            var areaName = routeData?.Values["area"]?.ToString();
            var area = string.IsNullOrWhiteSpace(areaName) ? string.Empty : areaName;

public void Configure(IApplicationBuilder app)
{
    ...

    app.UseRouting();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllers();
        endpoints.MapAreaControllerRoute(
            "admin", 
            "admin", 
            "Admin/{controller=Home}/{action=Index}/{id?}");
        endpoints.MapControllerRoute(
            "default", "{controller=Home}/{action=Index}/{id?}");
    });
}

public void Configure(IApplicationBuilder app)
{
    ...

    app.UseRouting();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapRazorPages();
    });
}