How to Hide the "Co-marquage SP" Admin Menu

function plt_hide_co_marquage_service_public_menus() {
	//Hide the "Settings → Co-marquage SP" menu.
	remove_submenu_page('options-general.php', 'comarquage-options');
}

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

Where do I put this code?