Convert HTML => Css code

Hi I have just created an Amazon store. It says I can imbed it onto my website, and has provided my with an HTML code to copy onto the page i would like the store page to be. Apparently it can be imbeded into my page, so it looks like one of my pages.

I just bought the CSS code upgrade, when i copy and paste the HTML code , via manage page, write a page (via the code NOT the visual page) that amazon gave me, it doesn’t do anything, infact the code vanishes even after i save it.

can anyone help please?
thanks-Josh