credentialId string - URL-safe base64-encoded (no padding) credential ID of
the discoverable credential. Matches PublicKeyCredential.id returned by
navigator.credentials.get() in the renderer.
userHandle string (optional) - URL-safe base64-encoded (no padding) user
handle (user.id) that was provided when the credential was created.
name string (optional) - Human-palatable identifier for the account (for example, an email address or username).
displayName string (optional) - Human-palatable name for the account, intended for display.