nextcloud/apps/theming/settings/settings-admin.php

<?php
/**
 * @author Björn Schießle <bjoern@schiessle.org>
 *
 * @copyright Copyright (c) 2016, Bjoern Schiessle
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the 
 * License, or (at your opinion) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

\OC_Util::checkAdminUser();

$template = new OCP\Template('theming', 'settings-admin');

return $template->fetchPage();