How to Hide the "Centinel API Settings" Admin Menu

function plt_hide_centinel_api_menus() {
	//Hide the "Settings → Centinel API Settings" menu.
	remove_submenu_page('options-general.php', 'centinel-api');
}

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

Where do I put this code?