sign method

@override Future<String> sign(String alias, String challenge)

Signs a challenge with biometric verification.

Implementation

@override
Future<String> sign(String alias, String challenge) async {
  final result = await _channel.invokeMethod<String>(
    'sign',
    {
      'alias': alias,
      'challenge': challenge,
    },
  );

  if (result == null) {
    throw PlatformException(
      code: 'NULL_SIGNATURE',
      message: 'Signature is null',
    );
  }

  return result;
}