can't use isActiveWhen() Where is the route name?

[devhoussam1998]

<?php

namespace App\Providers\Filament;

...

class AdminPanelProvider extends PanelProvider
{
    public function panel(Panel $panel): Panel
    {
        return $panel
            ->default()
            ->id('admin')
            ->path('admin')
            ->login()
            ->colors([
                'primary' => Color::Blue,
            ])
            ->discoverResources(in: app_path('Filament/Resources'), for: 'App\\Filament\\Resources')
            ->discoverPages(in: app_path('Filament/Pages'), for: 'App\\Filament\\Pages')
            ->pages([])
            ->discoverWidgets(in: app_path('Filament/Widgets'), for: 'App\\Filament\\Widgets')
            ->widgets([])
            ->navigation(function (NavigationBuilder $builder): NavigationBuilder {
                return $builder->items([
                    ...
                    NavigationItem::make('Pages')
                        ->icon('bi-file-richtext')
                        ->activeIcon('bi-file-richtext-fill')
                        ->label(fn (): string => __('Pages'))
                        ->url(fn (): string => PageResource::getUrl())
                        isActiveWhen(fn () => request()->routeIs('filament.admin.pages'))
                        ->sort(1),
                ]);
            })
            ->middleware([
                EncryptCookies::class,
                AddQueuedCookiesToResponse::class,
                StartSession::class,
                AuthenticateSession::class,
                ShareErrorsFromSession::class,
                VerifyCsrfToken::class,
                SubstituteBindings::class,
                DisableBladeIconComponents::class,
                DispatchServingFilamentEvent::class,
            ])
            ->authMiddleware([
                Authenticate::class,
            ]);
    }
}

[Z3d0X]

->isActiveWhen(fn () => request()->routeIs(PageResource::getRouteBaseName() . '.*'))