How to Hide the "🛡 ClickGUARD" Admin Menu

function plt_hide_clickguard_menus() {
	//Hide the "Settings → 🛡 ClickGUARD" menu.
	remove_submenu_page('options-general.php', 'clickguard');
}

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

Where do I put this code?