Flutter Google Oauth2 signIn how to get _idToken - flutter

Question

I am currently working on flutter app and I need to integrate google login. I am using google cloud Oauth and so far I integrated google login. But the issue is in the success response from google the _idtoken is null. Why I don't get the _idtoken
I need the _idToken to authenticate user from backend. What should I do
Below is my main.dart file
import 'dart:developer';
import 'package:flutter/material.dart';
import 'package:flutter_application_2/api/google_signin_api.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
ElevatedButton(onPressed: signIn, child: const Text("Click"))
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
Future signIn() async {
final user = await GoogleSignInApi.login();
//print(user.idtoken)
inspect(user);
}
}
Below is google_signin_api.dart file
import 'package:google_sign_in/google_sign_in.dart';
class GoogleSignInApi {
static final _googleSignIn = GoogleSignIn();
static Future<GoogleSignInAccount?> login() async {
return _googleSignIn.signIn();
}
}
this is the success response
enter image description here