Passport.js is an integration library for an identity system - so it's like a client library. As far as I know (it's been a while) it does not solve the "registration" or "password recovery" part itself. The system used in the blog post however does all of those things, from WebAuthn, to 2FA, to linking additional social sign in systems (e.g. Google or Twitter), and so on! So in this example, you could use Passport.js in combination with e.g. Ory Kratos. Hope this helps :)

I thought passport has libraries for the web server also