Custom Post Type Support

I'd like to suggest you add custom post type support. This way products, videos etc can be covered.

I've added my "video" type for now > class-nostrtium.php
if (($pagenow == 'post.php') && (get_post_type() == 'post') || (get_post_type() == 'video')) {

and the metabox render > class-nostrtium-metabox.php
$screens = ['post', 'video'];