Cross-domain problem using jquery, the value has been returned, and the error cannot be obtained

Question

Use the following code to obtain short links, but always report cross-domain issues

<script type="text/javascript">

$(function( )

{

var url2 = "http://8kgame.cn/api.php?d=";

var cmd = url2 "http://qudao .milygame.com/down/box/id/2/ag/<?php echo $chan['username']?>.html";

var message="";

$.ajax({ //Underlying method;

url: cm