Passwordless sign-in, approved on your phone. The website starts a request and shows a code; your phone (or the simulated one here) confirms it with a signature from an enrolled device key — no password is ever typed into the website.
A site you want to log in to. It never sees your password.
Approve this on your phone — it should show the same code:
Stands in for the Stelyph iOS app. Enroll this browser once with your password; after that it approves sign-ins with its device key — exactly what the app does behind Face ID.
None right now.