WP_REST_Server::READABLE, 'callback' => array($this, 'fb_test_function'), )); } public function fb_test_function(WP_REST_Request $request) { $parameters = $request->get_params(); // Create the response object $res = new WP_REST_Response(WC_Facebookcommerce_Utils::PLUGIN_VERSION); // Add a custom status code $res->set_status(200); $res->jsonSerialize(); return $res; } } endif;