If you have a security key, you can play with this workshop: https://slides.com/fidoalliance/jan-2018-fido-seminar-webauthn-tutorial#/

Also more materials on the subject are here: https://github.com/herrjemand/WebauthnAwesome

Lastly you should read my article “Introduction to WebAuthn API” https://medium.com/@herrjemand/introduction-to-webauthn-api-5fd1fb46c285

And DUO Security WebAuthn guide: https://webauthn.guide/