mikrotik port change?

hi
my connect this code. but api port change

 
 require_once 'PEAR2_Net_RouterOS-1.0.0b6.phar';
     $util = new RouterOS\Util($client = new RouterOS\Client($ip, $user_name, $password));

defualt port 8728 but my customer change port example 6105

how to this?

can you help?