How to Hide the "SCPOrder" Admin Menu

function plt_hide_simple_custom_post_order_menus() {
	//Hide the "Settings → SCPOrder" menu.
	remove_submenu_page('options-general.php', 'scporder-settings');
}

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

Where do I put this code?