我试图提交一个表单上的外部url，但我得到错误:你所要求的行动是不允许的

我试图自动提交表单上的cron到外部url在我制作脚本之后，我从外部站点

An Error Was Encountered
The action you have requested is not allowed.

这里是curl代码

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, "http://www.extsite.com/submit"); 
  curl_setopt($ch, CURLOPT_POST, true);
  curl_setopt($ch, CURLOPT_POSTFIELDS, array(
  'contenttitle' => '$title',
  'contentpath' => '$path',
  'submit' => 'submit'
  ));
  curl_setopt($ch, CURLOPT_HEADER, false);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
  $result = curl_exec($ch);
  echo "$result";