Device-Bound Passkeys iOS Credential Manager with FIDO2 Webauthn Flow

I'm looking for a very experienced iOS developer to create a credential manager app that primarily focuses on passwordless authentication using device-bound passkeys. This app should have the ability to support biometric authentication methods like Face ID and Touch ID, as well as device-bound passkeys.

We have a first app draft with AutoFill Extension and a custom RP Backend.
Very close to Keepass project: https://github.com/keepassium/KeePassium

Our app is logging a NotAllowedError in Webautn Flow (when we create give back our registrationobject that we customly built).

Key Features:
- Must respect and follow FIDO2 Webauthn Flow (registration, verification and authentication)
- Get Challenge from RP
- Must work with webauthn.io / Webauthn debugger and custom RP backend
- AuthenticationServices Library
- Biometric (Face-ID) verification
- Safari / Webclient Input Field Start for users
- Attestation Verification: The app should be able to verify the attestation of the passkeys
- SwiftCBOR Library Integration: The app should make use of the SwiftCBOR library for efficient CBOR (Concise Binary Object Representation) handling.
- Auto-fill for Web Forms: The app should include an autofill extension that can fill in web forms seamlessly.
- no keychain sync

Ideal candidates for this project should have:
- Proven experience in iOS development, particularly with Swift.
- Familiarity with implementing biometric authentication.
- Previous work integrating libraries such as SwiftCBOR.
- Experience developing autofill extensions.

Please provide examples of similar projects you have completed.