Fatal error: Uncaught Error: Class "Illuminate\Support\ServiceProvider" not found in /home/addup/public_html/panel/vendor/laravel/slack-notification-channel/src/SlackChannelServiceProvider.php:8 Stack trace: #0 {main} thrown in /home/addup/public_html/panel/vendor/laravel/slack-notification-channel/src/SlackChannelServiceProvider.php on line 8