Need random number generated in html for embedding into iframe

I am using this embed code for a site. The site is a Django site. I apologize if my terms are wrong, I'm not a developer.

. Periodically I return to the site and the graph will not display, but the logo from the host site does. I suspect that it's a caching issue. I tried "no-store" but I'm not sure if I pasted it in properly. I want to add a random number generator to the embed code. In my mind that would be similar to a refresh - again, not a programmer. Django strips css and possibly more. Can anyone either solve my problem or write the random number generator to make the "border-width" 1, 2, or 3? Here is my site with the bug. https://www.twelvebridges.com/twelve-bridges-market-report/. I encounter the bug on Chrome on a macbook. Never the first visit and a refresh solves it every time.

I tried "no-store" but probably in the wrong place. I tried Classic Cache Killer as a Chrome extension on my site. I added a gif on the site even though I cannot really articulate what I thought that would accomplish.