In reference to my comment. The first thing you have to solve is your cross origins problem. Most browsers will block requests to other websites if the response does not include the current host in their cross origins allow header. So in your case the header from your request to the iframe contents needs to include the header
Access-Control-Allow-Origin: http://159.89.229.184
and
Access-Control-Allow-Mehtods: GET
Also see https://de.wikipedia.org/wiki/Cross-Origin_Resource_Sharing for more info on this.
Now to the actual solution.
You need to determine the height of your iframes contents and then set the height accordingly. You can do this by adding a javascript function. In your head section add
<script>
const setHeight = (frame) => {
frame.style.height = `${frame.contentWindow.document.body.scrollHeight}px`
}
</script>
and your iframe needs to include the onload event
<iframe ... scrolling="no" onload="setHeight(this)" />
This should solve your problem. But as I mentioned just if you allow the cross origin access. Otherwise you access to the document of frame.contentWindow will get rejected with an error like
VM747:1 Uncaught DOMException: Blocked a frame with origin "http://159.89.229.184" from accessing a cross-origin frame.
I also made an example on glitch to demonstrate how it works (Click on Show to see it in action)
https://glitch.com/edit/#!/iframe-varialbe-height