sign method

@override String sign(String message)

Implementation

@override
String sign(String message) {
  final ecPrivateKey = ECPrivate.fromBytes(privateKey);
  if (isTaproot) {
    // Schnorr signature
    return ecPrivateKey.signTapRoot(message.toUint8List()).toHex();
  } else {
    return ecPrivateKey.signInput(message.toUint8List()).toHex();
  }
}