Want Firebase Phone Auth to link with Email and then only proceed

I want user to move only further if the OTP is correct and then create an account with Email and then link it with phone credentials. And for this I am trying the following.. I have tried making changes here and there but no success.. If the OTP is wrong it still moves further and creates an account with email and password. What I am doing wrong here pls correct me. Thanks.

    Future<void>verifyPhone(String code){

try{
  AuthCredential phoneAuthCredential = PhoneAuthProvider.credential(verificationId: vid, smsCode: code);

  auth.signInWithCredential(phoneAuthCredential).then((valueSignIn){
      auth.createUserWithEmailAndPassword(email: _email, password: _password).then((valueEmail) {
        auth.currentUser.linkWithCredential(phoneAuthCredential).then((valueLink) {
          insertData();
          Navigator.push(context, MaterialPageRoute(builder: (context)=>HomeScreen()));

        }).catchError((err){print("phone auth error 1: $err");
          print("phone auth error code 1: ${err.code}");
          if(err.code == "invalid-verification-code"){
            Fluttertoast.showToast( msg: "Invalid OTP, Try Again Or Check Your Phone Number",
                toastLength: Toast.LENGTH_SHORT,
                gravity: ToastGravity.BOTTOM,
                timeInSecForIosWeb: 3,
                backgroundColor: Colors.blueGrey,
                textColor: Colors.white,
                fontSize: 16.0);
          }else{
            Fluttertoast.showToast( msg: "Something Went Wrong, Try Again",
                toastLength: Toast.LENGTH_SHORT,
                gravity: ToastGravity.BOTTOM,
                timeInSecForIosWeb: 3,
                backgroundColor: Colors.blueGrey,
                textColor: Colors.white,
                fontSize: 16.0);
          }
        }).catchError((err){
          print("phone auth error 2: $err");
          print("phone auth error code 2: ${err.code}");
          if(err.code == "invalid-verification-code"){
            Fluttertoast.showToast( msg: "Invalid OTP, Try Again Or Check Your Phone Number",
                toastLength: Toast.LENGTH_SHORT,
                gravity: ToastGravity.BOTTOM,
                timeInSecForIosWeb: 3,
                backgroundColor: Colors.blueGrey,
                textColor: Colors.white,
                fontSize: 16.0);
          }else{
            Fluttertoast.showToast( msg: "Something Went Wrong, Try Again",
                toastLength: Toast.LENGTH_SHORT,
                gravity: ToastGravity.BOTTOM,
                timeInSecForIosWeb: 3,
                backgroundColor: Colors.blueGrey,
                textColor: Colors.white,
                fontSize: 16.0);
          }
        });

      });
    }).catchError((err){
    print("phone auth error 3: $err");
    print("phone auth error code 3: ${err.code}");
    if(err.code == "invalid-verification-code"){
      Fluttertoast.showToast( msg: "Invalid OTP, Try Again Or Check Your Phone Number",
          toastLength: Toast.LENGTH_SHORT,
          gravity: ToastGravity.BOTTOM,
          timeInSecForIosWeb: 3,
          backgroundColor: Colors.blueGrey,
          textColor: Colors.white,
          fontSize: 16.0);
    }else{
      Fluttertoast.showToast( msg: "Something Went Wrong, Try Again",
          toastLength: Toast.LENGTH_SHORT,
          gravity: ToastGravity.BOTTOM,
          timeInSecForIosWeb: 3,
          backgroundColor: Colors.blueGrey,
          textColor: Colors.white,
          fontSize: 16.0);
    }
  });

}catch(e){
  print("Phone Auth Credential $e");
}

}