60377: Authenticator attachment invalid or not provided

This error occurs when Verify Passkeys receives a request without a valid authenticatorAttachment value. Send the authenticatorAttachment returned in the WebAuthn credential object when you verify a Passkey factor or approve a Passkeys challenge. For those requests, Verify accepts only platform or cross-platform.

• Your request to VerifyFactor or ApproveChallenge does not include the required authenticatorAttachment field.
• Your request includes an unsupported value for authenticatorAttachment. For Passkey verification and challenge approval, supported values are platform and cross-platform.
• You sent any in the credential payload. any is allowed in Passkeys service or factor configuration, but it is not a valid value in the WebAuthn credential payload you send to VerifyFactor or ApproveChallenge.
• You rebuilt or filtered the browser credential object before sending it to Verify, and the authenticatorAttachment property was removed or renamed. The Passkeys quickstart shows authenticatorAttachment as part of the generated credential and instructs you to pass that copied JSON object to the Verify endpoint.

• Send the full browser credential object returned by navigator.credentials.create() or navigator.credentials.get() as JSON when you call VerifyFactor or ApproveChallenge.
• Validate that authenticatorAttachment is present before you send the request. Do not omit the field in registration or authentication payloads.
• Make sure the value is exactly platform or cross-platform when you submit the credential payload.
• If your Passkeys service or factor configuration uses any, keep that value only in configuration fields such as Passkeys.AuthenticatorAttachment or config.authenticator_attachment. Do not send any as the credential's authenticatorAttachment.
• Follow the Passkeys quickstart flow to create the factor or challenge, generate the credential in the browser, and then submit that copied credential object to Verify without changing field names.

• Verify Passkeys quickstart
• Passkeys Factor resource
• Passkeys Challenge resource