Try this code, which is more or less how Apple put it on their website. My old code (from Paul Hudson), which is still working perfectly fine on all pre-18 versions, did not work anymore, neither on-device nor in the simulator. func authenticate (completion: @escaping (Bool) -> Void) -> Void { let context = LAContext() Task { do { try await context.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: "Please authenticate to use the app.") completion(true) } catch { completion(false) } } }