Javascript JS：XML insertBefore插入元素

我有一个XML有效负载

   <myXML>
      <ctx>
       <recipient>
          <CardNumber>1245</CardNumber>
          <age>16</age>
          <height>180</height>          
       </recipient>
      </ctx>
   </myXML>


  var xmlDoc = DOMDocument.fromXMLString(message).getElementsByTagName("myXML")[0].toXMLString();

它基本上从CTX node 开始输出.

我想使用插入在特定位置添加一个新的 node /元素前面，但它对我不起作用，正确的方法是什么？

REF-https://experienceleague.adobe.com/developer/campaign-api/api/m-DOMNode-insertBefore.html

  xmlDoc.insertBefore("<email>david@garcia.com</email>","<CardNumber>");

我必须创建元素吗？如何将其插入到特定位置？使用insertBefore

  var email = xmlDoc.createElement("email");
      email.textContent = "david@garcia.com";
      email.appendChild(ctx)

以下是我如何做到这一点的

var myxml = <myXML>

       <recipient>
          <CardNumber>1245</CardNumber>
          <age>16</age>
          <height>180</height>          
       </recipient>
       <recipient2>
          <CardNumber1>1245</CardNumber1>
          <age>16</age>
          <height>180</height>          
       </recipient2>       
  
   </myXML>;

  var xmlDoc = new DOMDocument.fromXMLString(myxml);
  var root = xmlDoc.root;
  
    var ctx = xmlDoc.createElement("ctx");
  root.appendChild(ctx);
  
  var emailElem = xmlDoc.createElement("email");
  emailElem.textContent = "david@garcia.com";
  var parent = xmlDoc.getElementsByTagName("CardNumber")[0].parentNode;
  var email = xmlDoc.getElementsByTagName("CardNumber")[0];
  
  parent.insertBefore(emailElem, email);
  
logInfo(xmlDoc.toXMLString())

输出为

<?xml version='1.0'?>
<myXML>
  <recipient>
    <email>david@garcia.com</email>
    <CardNumber>1245</CardNumber>
    <age>16</age>
    <height>180</height>
  </recipient>
  <recipient2>
    <CardNumber1>1245</CardNumber1>
    <age>16</age>
    <height>180</height>
  </recipient2>
  <ctx/>
</myXML>