如何在模块中使用ExpressionEngine表单验证类来重新填充模板中的表单？

$validation = \Config\Services::validation();
$validation->setRules([
    'username' => 'required|alpha_numeric',
    'email' => 'required|valid_email',
    'password' => 'required|min_length[8]',
]);

if ($validation->withRequest($this->request)->run() === false) {
    return view('form_view', [
        'validation' => $validation,
    ]);
}

<?php if ($validation->getErrors()) : ?>
    <ul>
        <?php foreach ($validation->getErrors() as $error) : ?>
            <li><?= $error ?></li>
        <?php endforeach ?>
    </ul>
<?php endif ?>