How to Hide the "GorillaDash" Admin Menu

function plt_hide_gorilla_dash_integration_menus() {
	//Hide the "Settings → GorillaDash" menu.
	remove_submenu_page('options-general.php', 'gorilladash-api');
}

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

Where do I put this code?