Flutter Not establishing connection with mySQL

This is my source code. I have internet permission in android manifest. I have also tried ip address instead of localhost. All my database and password is correct. I don't know how to detect this error.

class _MyHomePageState extends State<MyHomePage> {



  Future db() async {
    List name = [];
    List id = [];
    String url = "https://retoolapi.dev/GUILOx/data";
    final response = await http.get(Uri.parse(url));

    var responseData = json.decode(response.body);

    for (var singleUser in responseData) {
      id.add(singleUser["id"]);

      name.add(singleUser["name"]);
    }
    final conn = await MySQLConnection.createConnection(
      host: "localhost",
      port: 3306,
      userName: "root",
      password: "kl32K4893*",
      databaseName: "flutter",
    );

    await conn.connect();

    await conn.execute("CREATE TABLE users (id int , name varchar(255));");

    var len = id.length;
    for (var i = 0; i < len; i++) {
      await conn.execute(
          "INSERT INTO users (id, name) VALUES('${id[i]}', '${name[i]}');");
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      floatingActionButton: FloatingActionButton(
        onPressed: (){db();},
          backgroundColor: Colors.red,
          child: const Icon(Icons.add)
      ),
    );
  }
}