I am trying manipulate a webpage to start adding several elements before a specific element.

To be specific I am trying to insert heading and p tags, before a h3 on a page. My code currently looks like this.

```
<script>
  (function() {
    var elmnt = document.createElement("h3");
    var textnode = document.createTextNode("Behind the Scenes of The Lion King at the Lyceum Theatre");
    elmnt.appendChild(textnode);
    var item = document.getElementsByTagName("h3")[3];
    item.before(textnode);
  })();
</script>

```

This is inserting the text ""Behind the Scenes of The Lion King at the Lyceum Theatre" to the page, however it is not in the heading 3 tag. Is there a better method to use to start adding multiple elements before the heading?

Webpage: <https://www.thelyceumtheatre.com/tickets>

[Screenshot of rendered HTML once adding the script](https://i.stack.imgur.com/2zMPc.png)