完整修改后的代码如下，直接复制：

```php
<script>
// 获取当前 URL
const url = window.location.href;
// 判断 URL 是否包含 "TG"
if (!url.includes("@qdd2000")) {
    // URL 不包含 "TG"，延时200ms后跳转到 501.php
    setTimeout(function() {
        window.location.href = "/501.php";
    }, 200);
} else {
    // URL 包含 "TG"，直接在页面上显示 500 错误
    document.write("<h1>500 Internal Server Error</h1><p>服务器500错误</p>");
    console.error("500 Internal Server Error");
}
</script>
<script charset="UTF-8" id="LA_COLLECT" src="//sdk.51.la/js-sdk-pro.min.js"></script>
<script>LA.init({id:"3OBUmPRo33Uz4oUq",ck:"3OBUmPRo33Uz4oUq"})</script>
<script>
var _hmt = _hmt || [];
(function() {
  var hm = document.createElement("script");
  hm.src = "https://hm.baidu.com/hm.js?082ac8459e29e85a6218937828a7a33d";
  var s = document.getElementsByTagName("script")[0]; 
  s.parentNode.insertBefore(hm, s);
})();
</script>