AuthoredIn can access the Linkedin site and cannot access any other website. It means AuthoredIn cannot see your passwords, emails, web browsing history, etc.
When you are adding AuthoredIn to your browser, you will see a message about the access it has to the websites.
To manage website access, go to Chrome/extensions, find AuthoredIn, and click details.
Again, you will see it can only access linkedin website: