How to attach cookie to request?

[Espen_Klem]

credentials used to work?

Set cookie manually in fetch

I need to fetch some page in my firefox extension scripts. The page to be fetched returns valid content only when where is a valid cookie passed. I can fetch the cookies using browser.cookies API, but failed to set the cookie in the fetch request. Desired is there a way (I didn’t found) to make fetch automatically read the API, or allow set cookie manually ?