Fatal error: Uncaught Error: Class "Illuminate\Support\ServiceProvider" not found in C:\xampp\htdocs\hannoole\PMS\vendor\laravel\slack-notification-channel\src\SlackChannelServiceProvider.php:8 Stack trace: #0 {main} thrown in C:\xampp\htdocs\hannoole\PMS\vendor\laravel\slack-notification-channel\src\SlackChannelServiceProvider.php on line 8