PHP cURL GET Request to REST API not returning anything

Question

I'm trying to use the UMLS Search REST API . I successfully retrieved the TGT and The ST. However, when trying to do a search as mentioned in the documentations, I got no response at all. Here's my code:

<?php
$service_ticket='xxx' //ST retrieve earlier
$cURLConnection = curl_init();
curl_setopt($cURLConnection, CURLOPT_URL,"https://uts-ws.nlm.nih.gov/rest/search/current");
curl_setopt($cURLConnection, CURLOPT_RETURNTRANSFER, true);
//avoid unable to get local issuer certificate
 $values = array(
    'ticket' => $service_ticket,
    'string' => 'C0162565'
    );
$params = http_build_query($values);
curl_setopt($cURLConnection, CURLOPT_POSTFIELDS, $params); 
$qresult = curl_exec($cURLConnection);
curl_close($cURLConnection);
$jsonArrayResponse = json_decode($qresult,true);
print_r($jsonArrayResponse);
?>

Answer 1

The API expects a GET request, but using curl_setopt($cURLConnection, CURLOPT_POSTFIELDS, $params); is changing the request type to POST. removing this command and adding the parameters directly to the URL fixes the problem.