the method "sendOtp" isn't defined for class 'LoginPage' - flutter

Question

i am calling this method(sendOtp) from another class but getting error: the method "sendOtp" isn't defined for class 'LoginPage'
it is a phone authentication loginpage method to sendOtp
class LoginPage extends StatefulWidget {
#override
State<StatefulWidget> createState() {
return LoginPageState();
}
}
class LoginPageState extends State<LoginPage> {
Future<void> sendOtp() async {
final PhoneVerificationCompleted phoneVerificationCompleted =
(AuthCredential credential) {};
final PhoneVerificationFailed phoneVerificationFailed =
(AuthException exception) {
print("Login Faild due to $exception");
};
final PhoneCodeSent phoneCodeSent =
(String verificationId, [int forceResendingToken]) {
this.verificationId = verificationId;
};
final PhoneCodeAutoRetrievalTimeout phoneCodeAutoRetrievalTimeout =
(String verificationId) {
this.verificationId = verificationId;
print("time out");
};
await _auth.verifyPhoneNumber(
phoneNumber: _numberController.text,
timeout: Duration(seconds: 120),
verificationCompleted: phoneVerificationCompleted,
verificationFailed: phoneVerificationFailed,
codeSent: phoneCodeSent,
codeAutoRetrievalTimeout: phoneCodeAutoRetrievalTimeout);
}
----------------ANOTHER CLASS-------------------
class OtpScreen extends StatefulWidget {
final String _name,_number, _id;
OtpScreen(this._name, this._number, this._id);
#override
OtpScreenState createState() {
return OtpScreenState();
}
}
class OtpScreenState extends State<OtpScreen> {
final TextEditingController _otpController = TextEditingController();
var _auth = FirebaseAuth.instance;
LoginPage loginPage = LoginPage();
Widget resend() {
return FlatButton(
child: Text("Send Otp again"),
onPressed: () => loginPage.sendOtp(), //ERROR IS HERE: sendOtp isn't defined for class LoginPage
);
}
}

Answer 1

You can't just call a method of another class without any reference. If the method is in the parent widget, you can pass it down when calling the child widget. If the method is in the child, you can pass a GlobalKey from the parent to the child, add that key to the child, and then through the key call the methods of the child.
If the two widgets have no relation what-so-ever, then you would benefit from using an InheritedWidget or a State Management solution that allows you to pass methods around in your app.