Help to Integrate WooCommerce to PromoSoftware Rest API

Hi guys been trying to get WooCommerce to send customer details via API to PromoSoftware

Promosoftware api info

add_action('woocommerce_thankyou', 'send_order_to_ext'); 
function wdm_send_order_to_ext(  ){
$api = new RestClient(array(
'base_url' => "http://ift.tt/1K8olJY", 
'format' => "php",
));
$addArray=array(


$addArray['ContactFirstName'] = 'Dave',
 $addArray['ContactLastName']='Davison',
 $addArray['ContactEmail']='dave@dave.com',
 $addArray['ContactSalutation']='Davo',
 $addArray['CompanyId']=12,//INT


$result=$api->post('contact',$addArray),
 json_decode($result->response),//returnsstdClassobject
 json_decode($result->response,true),//returnsassocarray
);
var_dump($result);
}

Im using php-restclient from github...

totally lost here.. just need to be guided in the right direction.

Thanks