.ebextensions configuration for Codeigniter index.php problemin AWS elastic beanstalk

finally got it 
 created a file in nginx (/etc/nginx/conf.d/elasticbeanstalk/01modrewrite.conf)
code :
 location / {

        try_files $uri $uri/ /index.php?$query_string;

        # Remove from everywhere index.php
        if ($request_uri ~* "^(./)index\.php(/?)(.)") {
            return 301 $1$3;
        }
    }