settings.php

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Adds userbulkdelete link in admin tree.
 *
 * @package    tool_userbulkdelete
 * @copyright  2019 Liip
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
defined('MOODLE_INTERNAL') || die();

if ($hassiteconfig) {
    $url = $CFG->wwwroot . '/' . $CFG->admin . '/tool/userbulkdelete/index.php';
    $ADMIN->add('accounts', new admin_externalpage('userbulkdelete', get_string('menu', 'tool_userbulkdelete'), $url));
}