How to change or hide original path in core php

I want to hide my url path ,so that no one can see the actual path of my file location.

For Example ,for this path ->localhost/example/api/Provider/signup.php

i want to change it like following ,

localhost/Provider/signup

in my .htaccess if i write following ,it works

RewriteEngine On
RewriteRule ^signup?$ signup.php

but when i try to change like below it wouldn't work

RewriteEngine On
RewriteRule ^signup?$ api/Provider/signup.php