如何获取微信开放平台的预授权码

部分代码
$ch = curl_init();
$url="";
$data=array(
'component_appid'=>$APPID,
'component_appsecret'=>$SECRET,
'component_verify_ticket'=>$ticket['ticket']
);
$data=http_build_query($data);
//var_dump($data);

$ch = curl_init();//打开
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
$response = curl_exec($ch);
curl_close($ch);//关闭
$result = json_decode($response,true);