let configuration = AuthenticationService.Configuration(localizedRegistrationReason: // Text explaining to the user why we need their biometrics while registration,
                                                        localizedAuthenticationReason: // Text explaining to the user why we need their biometrics while authentication.
                                                        appleTeamIdentifier: // The Apple registered development team identifier.)
self.authenticationService =  AuthenticationService(configuration: configuration)

let configuration = AuthenticationService.PassKeyConfiguration(
                    relyingPartyIdentifier: "com.example.com",
                    displayName: "App name"
                )
self.authenticationService = AuthenticationService(configuration: configuration)

let deviceSupport: String = try authenticationService.checkSupport()

authenticationService.isDeviceRegistered(withAuthenticationInput: input /*The opaque string sdk input*/) { [weak self] result in
    switch result {
    case let .success(isRegistered):
        /// output is a Boolean indicating whether the current device is registered,
        /// then you can call `authenticate` function below.
    case let .failure(error):
        /// Error raised,
        /// for example if the device is not protected by either pass code, face Id, or fingerprint, or if device is not registered,
        /// then you can call `register` function below.
    }
}

// OR you can also use the async version of this function:

let isDeviceRegistered = try await authenticationService.isDeviceRegistered(withAuthenticationInput: input /*The opaque string sdk input*/)

authenticationService.register(withRegistrationInput: input /*The opaque string sdk input*/) { [weak self] result in
    switch result {
    case let .success(output):
        /// output is an opaque string that should be sent to Adyen backend API (depending on the use case) to be validated for registration to be finalized.
    case let .failure(error):
        /// Failure to register the device, for example if the device is not protected by either pass code, face Id, or fingerprint.
    }
}

// OR you can also use the async version of this function:

let sdkOutput = try await authenticationService.register(withRegistrationInput: input /*The opaque string sdk input*/)

authenticationService.authenticate(withAuthenticationInput: input /*The opaque string sdk input*/) { result in
    switch result {
    case let .success(output):
        /// output is an opaque string that should be sent to Adyen backend API (depending on the use case) to be validated for authentication to be finalized.
    case let .failure(error):
        /// Failure to authenticate, which usually means that the current account is not registered.
    }
}

// OR you can also use the async version of this function:

let sdkOutput = try await authenticationService.authenticate(withAuthenticationInput: input /*The opaque string sdk input*/)