Page not found after migrate

I have a drupal web site which we are adding CodeIgniter and using it for API calls/access. in our dev area it was working fine but we needed to move it to prod where it was setup a little different. It is not working in Prod, I get a 'page not found' error.

My current drupal site is on ubuntu below /var/www/. I moved the CodeIgniter to be in /var/www/mysite/codeigniter/

I have some code on my page that will tell me the url being called for our API and it is the same as what was being called when this was working in dev. When I take the URL that we use to call our API and paste it in a browser it will work in dev but not prod.

I have set the PATH_INFO variable in config.php to the different values and no change. Still can't figure this out.

Any help?

Is you dev server a windows system?
Is the error message a codeigniter message?

The filename of you controller right? Uppercase?

Check filename: https://github.com/kenjis/codeigniter3-filename-checker

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