Disable all js scripts on iframe pages such as alerts and pop-up windows_javascript skills

I encountered a problem when making a small software today, that is, I need to put an iframe in a page to preview the website, but the previewed website contains a lot of js scripts, such as pop-up windows and prompt boxes. The most disgusting thing is I kept setting it as homepage and adding it to favorites. I thought there should be a way to ban scripts in iframes, so I searched on Baidu and found a lot of new continents. So I solved the problem and recorded it for future inquiries and for everyone’s reference:

<iframe src="fillseo.html"></iframe>

There is a js script in fillseo.html, which contains alerts and pop-up windows. It’s disgusting, how can I disable them?
And this fillseo.html is a file in a different domain.

After reviewing countless relevant information, I found that the following code can completely solve this problem:

Program code one:

<noscript><iframe src=fillseo.html></iframe></noscript>

or

Program code two:

<iframe src="fillseo.htm" width="200" height="200" id="Pcyear"></iframe>
<script>
var fillseo_window=window.frames["Pcyear"];
fillseo_window.window.alert=function(){
alert("弹弹弹！");
//也可以写你想写的东东
};
</script>