I am working on an Add On that injects a website’s content into the iframe which is a sidebar for the extension on Firefox. I am having issues with this following error: “Content Security Policy: The page’s settings blocked the loading of a resource at https://extension-test.databread.com/ (“frame-src”).”
This only happens when I visit certain websites, and a few of these are sites the add-on needs to have access to like stripe.com. Apparently this is possibly a Headers issue? Does anyone know why this is happening and what needs to be changed to get this iframe to work?