Yii required checkbox with condition

I have an ActiveForm with four checkboxes:

<?= $form->field($model, 'admin')->checkbox() ?>

<?= $form->field($model, 'newsletterAccess')->checkbox() ?>

<?= $form->field($model, 'groupAccess')->checkbox() ?>

<?= $form->field($model, 'templateAccess')->checkbox() ?>

and when the first checkbox is checked (admin), the form can only be submitted when all four checkboxes are checked. What should my rule look like? I tried something like this:

[['newsletterAccess', 'groupAccess', 'templateAccess'], 'compare', 'compareValue' => true, 
            'when' => function ($model) {
                return $model->admin == 1;
            }

but it didn't work. Thanks for help.