小程序码接口调用时返回40066 invalid url hint

事先$ACCESS_TOKEN  已经获得

$qcode ="https://api.weixin.qq.com/cgi-bin/wxa/getwxacode?access_token=".$ACCESS_TOKEN."";
$param = json_encode(array("path"=>"pages/dlwz/dlwz","width"=> 300));
//错误码： 40066  string(67) "{"errcode":40066,"errmsg":"invalid url hints: [ffcDxJqge-Oo3aKA!]"}"