Fatal error: Uncaught Error: Class "Monolog\Handler\AbstractProcessingHandler" not found in /var/www/ticket-code/vendor/thibaud-dauce/laravel-mattermost-logger/src/MattermostHandler.php:10 Stack trace: #0 {main} thrown in /var/www/ticket-code/vendor/thibaud-dauce/laravel-mattermost-logger/src/MattermostHandler.php on line 10