.htaccess Remove filename from url - apache

Question

I'm trying to remove: "site.php" from my url:s, which look like
"example.com/custom-foldername/site.php", so the url:s would look like "example.com/custom-foldername"
Currently it's not working at all. Basically my site just doesn't change the url. I know that the .htaccess file is being read, because if i write junk code in it, it gives error 500.
Here is my current .htaccess code
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
Options -Indexes
RewriteRule ^site\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /site.php [L]
</IfModule>

Answer 1

The code you posted is a front-controller pattern - it rewrites every request for non-existent files to /site.php in the document root (not /custom-foldername/site.php).
And nor will a RewriteRule pattern like ^site\.php$ match a request like /custom-foldername if the .htaccess file is in the document root.
I'm trying to remove site.php from my URLs...
From all your URLs? Is site.php present in all your URLs? So, site.php is your front-controller?
If site.php really is your front-controller then try something like the following instead:
Options -Indexes
RewriteEngine On
RewriteBase /custom-foldername
RewriteRule site\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^ site.php [L]
This rewrites everything that doesn't map to a physical file or directory to /custom-foldername/site.php.

Answer 2

UPDATE: I solved this my myself while ago, but forgot to update
So, i found the solution and here's my current .htaccess file, if someone is ever having the same problem
RewriteEngine On
RewriteBase /
Options -Indexes
DirectoryIndex site.php site.html
When user "asks" for folder directory (example.com/cats) apache looks for "site.php or site.html" files inside it. (example.com/cats/site.php) If it finds either on of them it displays it to the user as (example.com/cats). If either file isn't found it gives normal "404 not found error"