I'm working on integrating Passkey functionality into my iOS app (targeting iOS 16.0+), and I'm facing an issue where the system dialog still shows the "Save to another device" option during Passkey registration. I want to hide this option to force users to create Passkeys only on the current device. 1. My Current Registration Implementation Here’s the code I’m using to create a Passkey registration request. I’ve tried to use ASAuthorizationPlatformPublicKeyCredentialProvider (which is supposed to target platform authenticators like Face ID/Touch ID), but the "Save to another device" option still appears: `// Initialize provider for platform authenticators let provider = ASAuthorizationPlatformPublicKeyCredentialProvider(relyingPartyIdentifier: domain) // Create registration request let registrationRequest = provider.createCredentialRegistrationRequest( challenge: challenge, name: username, userID: userId ) // Optional configurations (tried these but no effect on "another device" option) registrationRequest.displayName = "Test Device" registrationRequest.userVerificationPreference = .required registrationRequest.attestationPreference = .none // Set up authorization controller let authController = ASAuthorizationController(authorizationRequests: [registrationRequest]) let delegate = PasskeyRegistrationDelegate(completion: completion) authController.delegate = delegate // Trigger the registration flow authController.performRequests(options: .preferImmediatelyAvailableCredentials)` 2. Observation from Authentication Flow (Working as Expected) During the Passkey authentication flow (not registration), I can successfully hide the "Use another device" option by specifying allowedCredentials in the ASAuthorizationPlatformPublicKeyCredentialAssertionRequest. Here’s a simplified example of that working code: let assertionRequest = provider.createCredentialAssertionRequest(challenge: challenge) assertionRequest.allowedCredentials = allowedCredentials After adding allowedCredentials, the system dialog no longer shows cross-device options—this is exactly the behavior I want for registration. 3. My Questions Is there a similar parameter to allowedCredentials (from authentication) that I can use during registration to hide the "Save to another device" option? Did I miss any configuration in the registration request (e.g., authenticatorAttachment or other properties) that forces the flow to use only the current device’s platform authenticator? Are there any system-level constraints or WebAuthn standards I’m overlooking that cause the "Save to another device" option to persist during registration? Any insights or code examples would be greatly appreciated!