cat addorder_and_registrar_set_default.php
#!/usr/bin/php
<?php
error_reporting(E_ALL);

$url = "http://my.web-singularity.eu/includes/api.php"; # URL to WHMCS API file goes here
$username = "S7G2VFAxdXgBXSVbd6SKUDPiNKM7eElC"; # Admin username goes here
$password = "yXNJWsdJQSHPDGVTvbqLl6N6OI57bniI"; # Admin password goes here

$postfields = array();
$postfields["username"] = $username;
$postfields["password"] = md5($password);
$postfields["action"] = "addorder";
$postfields["clientid"] = 3;
$postfields["pid"] = ["1", '1'];
$postfields["domain"] = ['exampdsafdlasdfasde.eu', 'easdfasdfasdfadsxamle2.eu'];
$postfields["billingcycle"] = "monthly";
$postfields["addons"] = "";
$postfields["registrar"] = "versio";
$postfields["domaintype"] = ["register", 'register'];
$postfields["regperiod"] = [1, 2];
$postfields["paymentmethod"] = "paypalnofees";
$postfields['responsetype'] = 'json';

//$query_string = null;
//foreach ($postfields AS $k=>$v) $query_string .= $k.'='.urlencode($v).'&';

$str = http_build_query($postfields, '', "&");

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $str);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
$jsondata = curl_exec($ch);
if (curl_error($ch)) die("Connection Error: ".curl_errno($ch).' - '.curl_error($ch));
curl_close($ch);

$arr = json_decode($jsondata, true); # Decode JSON String

print_r($arr); # Output XML Response as Array

//$orderid = $arr['orderid'];

//$postfields = null;
//$postfields = array();
//$postfields["username"] = $username;
//$postfields["password"] = md5($password);
//$postfields["action"] = "acceptorder";
//$postfields["orderid"] = $orderid;
//$postfields['registrar'] = 'versio';
//$postfields['autosetup'] = '0';
//$postfields['sendregistrar'] = '0';
//$postfields['responsetype'] = 'json';

//$str = http_build_query($postfields, '', "&");

//$ch = curl_init();
//curl_setopt($ch, CURLOPT_URL, $url);
//curl_setopt($ch, CURLOPT_POST, 1);
//curl_setopt($ch, CURLOPT_TIMEOUT, 30);
//curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
//curl_setopt($ch, CURLOPT_POSTFIELDS, $str);
//curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
//curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
//$jsondata = curl_exec($ch);
//if (curl_error($ch)) die("Connection Error: ".curl_errno($ch).' - '.curl_error($ch));
//curl_close($ch);

//$arr = json_decode($jsondata, true); # Decode JSON String

//var_dump($arr); # Output XML Response as Array