add_action( 'init', function() { global $wp_post_types; if ( isset( $wp_post_types['serial'] ) ) { $wp_post_types['serial']->show_in_rest = true; $wp_post_types['serial']->rest_base = 'serial'; } }, 25 );add_action( 'rest_api_init', function() { global $wp_post_types; if ( isset( $wp_post_types['serial'] ) ) { $wp_post_types['serial']->show_in_rest = true; $wp_post_types['serial']->rest_base = 'serial'; $wp_post_types['serial']->rest_controller_class = 'WP_REST_Posts_Controller'; } }, 99 );