Add “Featured Image” box in my plugin post page

You can add that featured image metabox you’ve circled to your custom post type by doing:

register_post_type( 'yourCPTslug', [
    //...
    'supports' => ['title', 'editor', 'thumbnail'] // note: thumbnail
] );


add_action( 'after_setup_theme', function () {
    add_theme_support( 'post-thumbnails' , ['yourCPTslug'] );
});

As for a single function calling it in a position where you want it – I’m fairly certain no.