How to Hide WP Customer Area Admin Menus

function plt_hide_customer_area_menus() {
	//Hide "Settings → WP Customer Area".
	remove_submenu_page('options-general.php', 'wpca-settings');

	//Hide "Private area".
	remove_menu_page('wpca');
	//Hide "Private area → About".
	remove_submenu_page('wpca', 'wpca');
	//Hide "Private area → Files".
	remove_submenu_page('wpca', 'wpca-list,content,cuar_private_file');
	//Hide "Private area → Pages".
	remove_submenu_page('wpca', 'wpca-list,content,cuar_private_page');
	//Hide "Private area → Logs".
	remove_submenu_page('wpca', 'wpca-logs');
	//Hide "Private area → Status".
	remove_submenu_page('wpca', 'wpca-status');
}

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

Where do I put this code?