HB seo url not working

[Saahib]

I can't get it index.php removed from url.

As per details here : https://hostbill.atlassian.net/wiki/spaces/DOCS/pages/492176/SEO-friendly+URLs+in+HostBill

I added  $ca_url_prefix="/";  in includes/config.php  but URL created by HB are still showing index.php in urls

Note : I am not talking about server side settings, that's another part, first HB is supposed to create links without "index.php" in it, but its not doing so.