I am using Wamp server, i pull the project and in index.php there is
require_once ('app_config_new.php')
I have a file structure as follows:
what should i change in apache config file to work this code
It has nothing to do with Apache configuration.
In file index.php you must set the path to app_config_new.php, like this:
require_once(__DIR__ . '/config/app_config_new.php');
The answer provided by @David Zadražil is the desired one, but if you can't or don't want to change the code, you can change include_path in your php.ini to include the directory with app_config_new.php:
include_path=".;c:\your_path_to_project\config"
Restart you Apache (if using mod_php) or PHP-FPM afterwards.