A simple PHP WebAuthn (FIDO2) server library.
Simple working demo for the lbuchs/WebAuthn library.
Relying Party

A valid domain string that identifies the WebAuthn Relying Party
on whose behalf a given registration or authentication ceremony is being performed.

attestation statement format
user verification
type of authenticator
root certificates
(Nothing checked = accept all)
If you select a root ca, direct attestation is required to validate your client with the root.
The browser may warn you that he will provide informations about your device.
When not checking against any root ca (deselect all certificates), the client may change the assertion from the authenticator (for instance, using an anonymization CA),
the browser may not warn about providing informations about your device.

Here you can see what's saved on the server: