Background emailer file changes not showing? (Curl & AWS SES)

This is a general question not related to laravel however, would really appreciate any help.

I am trying to make changes to a php file called _backgroundEmailer.php which checks the database to see if there is any emails in the queue and sends them using CURL through AWS SES.

But no changes are being shown at all even if I uncomment the whole page it will still work, but I know for a fact that I am editing the right file.

so I want to know do I have to restart something or do anything to the server for the changes to show and be detected?

And any ideas how the file is executed in the background as I am not very experienced myself.

Thanks in advance.