Tips on Customizing Cool Flipbox – Shortcode & Gutenberg Block

How to Hide Cool Flipbox Admin Menus

function plt_hide_flip_boxes_menus() {
	//Hide "Settings → Cool Flipbox".
	remove_submenu_page('options-general.php', 'cfb_settings');

	//Hide "Cool Flipbox".
	remove_menu_page('edit.php?post_type=flipboxes');
	//Hide "Cool Flipbox → All Flipbox".
	remove_submenu_page('edit.php?post_type=flipboxes', 'edit.php?post_type=flipboxes');
	//Hide "Cool Flipbox → Add New".
	remove_submenu_page('edit.php?post_type=flipboxes', 'post-new.php?post_type=flipboxes');
}

add_action('admin_menu', 'plt_hide_flip_boxes_menus', 11);

Where do I put this code?

How to Hide the "Use This Shortcode" Meta Box

function plt_hide_flip_boxes_metaboxes() {
	$screen = get_current_screen();
	if ( !$screen ) {
		return;
	}

	//Hide the "Use This Shortcode" meta box.
	remove_meta_box('my-meta-box-id', $screen->id, 'side');
}

add_action('add_meta_boxes', 'plt_hide_flip_boxes_metaboxes', 20);