hi i'm having the following error in laravel on my ubuntu server yet the same exact code works on my local host

[the image shows the error screen, so i'm also wondering where to start debugging from..][1]``` Symfony\Component\Debug\Exception\FatalThrowableError thrown with message "Parse error: syntax error, unexpected '?'"

Stacktrace: #0 Symfony\Component\Debug\Exception\FatalThrowableError in /var/www/html/awsmonitor/aws-monitor/vendor/symfony/css-selector/Node/SelectorNode.php:40

  [1]: https://i.stack.imgur.com/PvPsL.png

via Chebli Mohamed