Yes, my idea is that you declare a content script that will run inside that iframed site. It will receive the cookies via extension messaging and set them via `document.cookie` as session cookies. An entirely different approach would be to use `chrome.cookies` API. – wOxxOm Mar 26 '21 at 14:35

@wOxxOm I think I got it now. Would you provide me a code sample how to send a message from the iframed site, please? – l000p Mar 26 '21 at 18:51

@wOxxOm I have created a content script that runs inside that framed site. It sets some cookies with `document.cookie` and after that `console.log(document.cookie)`, unfortunately it log an empty string. I must be missing something here. – l000p Mar 29 '21 at 15:03