The download is usually a compressed .zip file. Extract it to get the .bin image.
You now have a bootable Chrome OS Flex USB drive. While it’s not an .iso , it serves the exact same purpose. download chrome os flex iso
On a working PC or Mac, open the Chrome browser and install the Chromebook Recovery Utility from the Chrome Web Store. SEO-ready blog post: "Download Chrome OS Flex ISO
Hit "Generate & Copy" button to generate embed code. It will be copied to your Clipboard. You can now paste this embed code inside your website's HTML where you want to show the List.