Yii2: How to get checkox's value from controller

I need to get the value of a checkbox called Password using the Yii2 Framework, in the controller.

In my _form.php I define the checkbox:

<?= Html::checkbox('password', false, $options = ['label' => 'Reset password']) ?>

In my UserController.php I have the actionUpdate function:

public function actionUpdate($id)
{
    $model = $this->findModel($id);
     if ($model->load(Yii::$app->request->post()) && $model->save()) {
        return $this->redirect(['view', 'id' => $model->id]);
    } else {
        echo '<pre>';
        echo Yii::$app->request->post()['password'];
        echo '</pre>';
        return $this->render('update', [
            'model' => $model,
        ]);
    }
}

I always get the value 1 instead of true or false.