class AppRouterFactory
{
    public function __invoke(ContainerInterface $container)
    {
        $routes = [
            Route::get('/test', [SiteController::class, 'test2'])->name('test')
            ];

        $router = (new RouterFactory(new FastRouteFactory(), $routes))($container);
        $router->setUriPrefix('/admincp');
        return $router;
    }
}

public function test2(RouterInterface $router, ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
    {
        $response = $this->responseFactory->createResponse();
        $response->getBody()->write($router->generate('test'));

        return $response;
    }