# signMessage()

**Method Signature:**

```dart
String signMessage(String plainMessage, String privateKey);
```

**Parameters**

| Name         | Type   | Description                                                         |
| ------------ | ------ | ------------------------------------------------------------------- |
| plainMessage | String | Message that you want to sign. In transactions it must be the TxID. |
| privateKey   | String | Private key in hexadecimal format.                                  |

**Example**

```dart
import 'package:circular_api/circular_api.dart';

void main() {
  final circular = CircularAPI();

  final privateKey = "0x248ea24763f3aeb2590114257b0b95ebc8fc40e287574aa25379bb24c6d661ec";
  final message = "Hello, World!";
  
  final signedMessage = circular.signMessage(message, privateKey);
  print(signedMessage);
}
```

**Result**

The result will be a String object:

```bash
6aa65e46e2db7fe30c7ea68c931e26f1a97f60f35745b25b1baec250f62432e670b0267dd7e3d78e02e5dc6fc2db0aa720d6db617b9cb251403aec5aec03e582
```