As far as I'm aware that tool gets the info necessary to make requests to the API from the browsers cookies as requests to Fansly's API doesn't require that many headers. OF doesn't store everything you need to make requests to OF's API in the browser, you need to manually retrieve it from the dev tools. Any requests you make to OF's API need the correct headers and if any of them are wrong then you'll be logged out of that session and you'll have to log in again and get the new session information.