Why is mod_rewrite not working despite being enabled?
If you are not sure whether mod_rewrite is enabled, please see the following article.
How do I verify an Apache module is enabled for my server?
Once mod_rewrite is enabled, it will require that rules be placed within a website's .htaccess file in order for it to be usable. A mod_rewrite rule will look something like this.
<IfModule mod_rewrite.c> RewriteEngine On RewriteRule $somerule </IfModule>
$somerule being replaced with an actual mod_rewrite rule. For information on how to use mod_rewrite with your .htaccess file, please see the official documentation here.