iFrame. All you need for this is the URL of the live form.
Here’s a code example of how to embed a form in an iframe.
<iframe frameborder="0" width="100%" src="FORM_URL?embed=1&inline=1" height="HEIGHT"></iframe>
Just replace FORM_URL with the full URL to the form (don’t forget the “https://” part!).
You’ll also need to set the height of the iFrame by replacing HEIGHT with the height the form needs to display in pixels. If the form is taller than the height you specify the form will scroll inside of the iFrame, otherwise, it will sit neatly on the page. If you’re unsure what to put as the height, try “400” to get started, you can always change it later.
Note that there are a few downsides to using an iFrame directly;