Laravel - can't find any entry where I can fill an ip address of the LDAP server

I have a Nas where a directory server(LDAP) is, and would like to connect my web server where my Laravel project is to it. However, for the Adlp library below, no entry to fill an ip address of the directory server(LDAP) in.

https://github.com/adldap/adLDAP

$config = array(
    'account_suffix' => "@gatech.edu",

    'domain_controllers' => array("whitepages.gatech.edu"),

    'base_dn' => 'dc=whitepages,dc=gatech,dc=edu',

    'admin_username' => '',

    'admin_password' => '',
);

$ad = new Adldap($config);

via Kang Andrew