Fatal error: Uncaught Error: Class "Symfony\Component\Mailer\Transport\RoundRobinTransport" not found in /var/www/html/booking/vendor/symfony/mailer/Transport/FailoverTransport.php:19 Stack trace: #0 {main} thrown in /var/www/html/booking/vendor/symfony/mailer/Transport/FailoverTransport.php on line 19