Stolen from
gist@MasterKale/dbe39a01438251f0cbd55576304731fd
Read Mathews blog
https://blog.millerti.me/2023/01/22/encrypting-data-in-the-browser-using-webauthn/
Open your dev console before clicking either of these!
FYI both steps are required on every reload, nothing persists.
Register
Check for "PRF supported: true" in the console before continuing
Authenticate