$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,"https://platform.devtest.ringcentral.com/restapi/v1.0/account/~/extension/~/ring-out");
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS,
http_build_query(array('from' => '+12048184079',
'to' => '+17604762222'
)));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$headers = [
"Content-Type: application/json",
"Accept: application/json",
"Authorization: Bearer U0pDMTFQMDFQQVMwMHxBQUFtdWhQcG5lYk4xbUIwc2pyaXpqTVZJZnlxUWhENlEtc2NRcTNxYmZaRXl5Qk9nSWk2RDFiMjVFTy0zaXhsVGlWNF9QWWRPMEVYNENYQjd4dmJsWHJoVTBsTVl2VlA1XzNIczcycTVONm13eDY5d3o3YWkwN3l5Wkt3clFLVDl0Y3FmajJQZ0tRSUtmRnhjNGJua1lHbmxxSElJTzBnOUxab0dZR19MVlo5bGhDU2pMcE1oYm5jRG9icVRYbUswSm14VzI3VmdrNjR2aVZxUGt6bU9aOUN8amhaMGtnfFZFM1ZGamhpaTdKcjc2dkRzSDEzMGd8QUE"
];
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
$server_output = curl_exec($ch);
echo "<pre>"; print_r($server_output); die;
curl_close ($ch);
output: -
{ "errorCode" : "InvalidJson", "message" : "Unrecognized token 'from': was expecting 'null', 'true', 'false' or NaN
at line: 1, column: 6", "errors" : [ ]
}