I am working on flutter and i have overriden initState() and overriden Widget build()
So when i assigned value to a variable inside overriden initState() and using that variable inside the overriden Widget build(), i am getting the variable as null. someone please help me

dynamic database_functions = FirebaseMethods();

class RenderProfileView extends StatefulWidget {
  String email;
  RenderProfileView(this.email, {super.key});

  @override
  State<RenderProfileView> createState() => _RenderProfileViewState();
}

class _RenderProfileViewState extends State<RenderProfileView> {
  TextEditingController name_controller = TextEditingController();
  TextEditingController phone_number_controller = TextEditingController();

  dynamic? user_json;  // this is the variable i am assigning value inside initState()

  String name = "";
  String phone_number = "";
  dynamic edit_or_display_name = ProfileName();
  dynamic edit_or_display_phone_number = ProfilePhoneNumber();
  dynamic edit_or_save_icon = Icons.edit;
  dynamic edit_or_save_text = "Edit";
  String error_message = "";

  @override
  void initState() {
    super.initState();
    getUserData();
  }

  void getUserData() {
    database_functions.findUsers('email', widget.email).then((value) {
      setState(() {
        print(value);  // this line not executing before the print statement that i have given in the Widget build()
        user_json = value;
        name = value[0].name;
        phone_number = value[0].phone;
      });
    });
  }

  dynamic get_name() {
    return name_controller.text;
  }

  void clear_name() {
    name_controller.text = "";
  }

  dynamic get_phone_number() {
    return phone_number_controller.text;
  }

  void clear_phone_number() {
    phone_number_controller.text = "";
  }

  void changer() {
    setState(() {
      if (edit_or_display_name.runtimeType == NameField) {
        String newName = get_name();
        String newPhoneNumber = get_phone_number();
        if (name_validator(newName) == true && phone_number_validator(newPhoneNumber) == true) {
          name = newName;
          phone_number = newPhoneNumber;
          clear_name();
          clear_phone_number();
          edit_or_display_name = ProfileName();
          edit_or_display_phone_number = ProfilePhoneNumber();
          edit_or_save_icon = Icons.edit;
          edit_or_save_text = "Edit";
          error_message = "";
        } else {
          if (name_validator(newName) == false) {
            error_message = "Invalid format for name!";
          } else {
            error_message = "Invalid format for phone number!";
          }
        }
      } else {
        edit_or_display_name = NameField(name_controller, get_name, clear_name);
        edit_or_display_phone_number = PhoneNumberField(phone_number_controller, get_phone_number, clear_phone_number);
        edit_or_save_icon = Icons.save;
        edit_or_save_text = "Save";
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    print(user_json);  // this is giving me null
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Scaffold(
        appBar: AppBar(
          title: Text('Profile'),
          actions: <Widget>[
            TextButton(
              style: flatButtonStyle,
              onPressed: () => changer(),
              child: IconTextPair(edit_or_save_icon, edit_or_save_text, Colors.white,),
            ),
          ],
          backgroundColor: Colors.blue,
          foregroundColor: Colors.white,
        ),
        backgroundColor: Colors.white,
        body: ProfilePage(name, widget.email, user_json[0]['rollno'], phone_number, user_json[0].batch, user_json[0].dept, user_json[0].gender, ["a", "b", "c", "d"], user_json[0].photoImgLink, edit_or_display_name, edit_or_display_phone_number, error_message),  // this line gives me the following error : Error: NoSuchMethodError: '[]'
      ),
    );
  }
}

and this is my firebase functions’ class

class FirebaseMethods {
  Future<List> findEvents(dynamic attribute, dynamic value) async {
    CollectionReference eventCollection =
        FirebaseFirestore.instance.collection('events');
    return eventCollection
        .where(attribute, isEqualTo: value)
        .get()
        .then((QuerySnapshot querySnapshot) {
      List events = [];
      querySnapshot.docs.forEach((doc) {
        events.add(doc.data());
      });
      return events;
    }).catchError((error) {
      print("Failed to retrieve events: $error");
    });
  }

  Future<List> findUsers(dynamic attribute, dynamic value) async {
    CollectionReference userCollection =
        FirebaseFirestore.instance.collection('profile');
    return userCollection
        .where(attribute, isEqualTo: value)
        .get()
        .then((QuerySnapshot querySnapshot) {
      List users = [];
      querySnapshot.docs.forEach((doc) {
        users.add(doc.data());
      });
      return users;
    }).catchError((error) {
      print("Failed to retrieve users: $error");
    });
  }
}

someone please help me