How to Hide the "DH – Rename Uploaded Files" Admin Menu

function plt_hide_dh_rename_uploaded_files_menus() {
	//Hide the "Settings → DH – Rename Uploaded Files" menu.
	remove_submenu_page('options-general.php', 'dh-rename-uploaded-files');
}

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

Where do I put this code?