Issues with iframes

I struggle with a big issue for me. I need embed a portfolio of artworks from platform. I used iframe element to embed it. So I did it, but have iissues with the layout. How to reduce margines, hide additional sliders, if I add works to portfolio the section does not extend down, it cuts the content and stay fixed, how to make the section flexible to content?

HTML code got fixed height, you need to fix this and give section additional space for min H, please see the example attached:

and here are some materials on embeds sizing:

It’s difficult to say since the code and site within the iFrame can’t really be controlled but there are some ways to adjust the content if the height and width are pre-defined: