Move the metaboxes to the very top of post editor

Found the solution 🙂

add_action('edit_form_after_title', function() {
    global $post, $wp_meta_boxes;
    do_meta_boxes(get_current_screen(), 'advanced', $post);
    unset($wp_meta_boxes[get_post_type($post)]['advanced']);
});
add_action('add_meta_boxes', 'generator_api');