Hmm, couldn't find documentation, so I tried looking for the source to see how auth worked.

Package has no README https://www.npmjs.com/package/file0 nor links to a repo

Searching Github doesn't give anything (nor any public projects using it).

Installing the package from NPM just gives you a completely minified JS that's pretty difficult to understand https://www.npmjs.com/package/file0?activeTab=code. No need to publish minified JS to NPM imho. Actually reading/stepping through dependencies is always exceptionally valuable.