Email Verification is not working in flutter firebase - flutter

Question

I'm following a flutter firebase tutorial, and now i'm trying to verify my signing using Email , the problem is that it does not seem to work , and when i try to verify again , it gives me an FirebaseauthException cause i'm trying too much (as the exception said) to verify the email , which may be weird to FireBase , but why isn't working in the first time,
here is the code , i've tried to print some thing after the line that should send the request to verify , and it worked! :
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';
import 'package:flutter/src/foundation/key.dart';
import 'package:flutter/src/widgets/framework.dart';
class Test extends StatefulWidget {
const Test({Key? key}) : super(key: key);
#override
State<Test> createState() => MyState();
}
class MyState extends State<Test> {
UserCredential? usercredential;
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text("Test")),
body: Column(mainAxisAlignment: MainAxisAlignment.center, children: [
Center(
child: RaisedButton(
onPressed: () async {
try {
usercredential = await FirebaseAuth.instance
.signInWithEmailAndPassword(
email: 'hamzafz888#gmail.com',
password: "verysecretpassword!");
print("Signed in with temporary account.");
} on FirebaseAuthException catch (e) {
if (e.code == 'user-not-found') print("no user in this email");
if (e.code == 'wrong-password') print("wrong password inserted");
} catch (e) {
print("UNKOWN ERROR");
}
// print(usercredential!.user!.emailVerified);
if (!usercredential!.user!.emailVerified) {
User? user1 = FirebaseAuth.instance.currentUser;
await user1!.sendEmailVerification();
//print("hello");
}
},
child: Text("Sign In"),
))
]),
);
}
}