Info.plist add item like that ASCredentialProviderExtensionCapabilities ProvidesPasskeys

For example, at webauthn.me, the parameters uploaded by the agent include: user: { id:Regenerate (binary, random) name:test displayName:Test User } Challenge: Regenerate (binary, random) two information user.id & challenge. After clicking "Register", this method is invoke. How can these two information user.id&challenge information be obtained?