autocde2.0/app/Services/Notification/ActionBrowser/RequirementNotification.php

<?php

namespace App\Services\Notification\ActionBrowser;

use App\Services\Notification\Abstracts\ActionBrowserNotificationAbstract;

class RequirementNotification extends ActionBrowserNotificationAbstract
{
    protected function userIDs(): array
    {
        return $this->object->mailto > 0 ? $this->object->mailto :[];
    }
}