File Content: Oxygen.php <?php namespace MetaBox\Integrations; class Oxygen { public function __construct() { add_action( 'oxygen_add_plus_sections', [ $this, 'add_metabox_category' ] ); } public function add_metabox_category() { if ( ! defined( 'CT_VERSION' ) ) { return; } \CT_Toolbar::oxygen_add_plus_accordion_section( 'meta-box', esc_html__( 'Meta Box', 'wgl-extensions' ) ); } } Submit