ios – ib/primary.dart:49:24: Error: The operator ‘[]’ is not outlined for the category ‘Set>’

import 'package deal:flutter/materials.dart';
import './query.dart';
import './reply.dart';

void primary() {
  runApp(MyFirstApp());
}

class MyFirstApp extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    // TODO: implement createState
    return _MyFirstAppState();
  }
}

class _MyFirstAppState extends State<MyFirstApp> {
  var _questionIndex = 0;
  void _ansButtonPress() {
    setState(() {
      _questionIndex = _questionIndex + 1;
    });
  }

  var questions = [
    {
      'questionText': 'What is  your favorate Colour',
      'answers': ['red', 'balck ', 'yellow', 'blue']
    },
    {
      'questionText': 'What's  your favorate Animal',
      "solutions": ['Lion', 'Chettah ', 'Leopard', 'Cat']
    },
    {
      'questionText': 'What's  your favorate Film',
      'solutions': ['hai', 'hello ', 'hoe', 'are you']
    }
  ];

  Widget construct(BuildContext context) {
    return MaterialApp(
      house: Scaffold(
        appBar: AppBar(
          title: Textual content('My first app '),
        ),
        physique: Column(
          youngsters: [
            Question(
              questions[_questionIndex]['questionText'],
            ),
            Reply(_ansButtonPress),
            Reply(_ansButtonPress),
            Reply(_ansButtonPress),
          ],
        ),
      ),
    );
  }
}

error in line 49

terminal displaying like this

lib/primary.dart:49:24: Error: The operator ‘[]’ is not outlined for the
class ‘Set<Map<String, Object>>’.
– ‘Set’ is from ‘dart:core’.
– ‘Map’ is from ‘dart:core’.
– ‘Object’ is from ‘dart:core’.
Strive correcting the operator to an current operator, or defining a ‘[]’ operator.
questions[_questionIndex][‘questionText’],
^
Didn’t package deal /Customers/j3rry01/Paperwork/Flutter Lab/flutter fundamentals /new_flutter.
Command PhaseScriptExecution failed with a nonzero exit code
word: Utilizing new construct system
word: Planning
word: Construct preparation full
word: Constructing targets in parallel
warning: Capabilities for Signing & Capabilities could not operate appropriately as a result of its entitlements use a placeholder group ID. To
resolve this, choose a
improvement group within the Runner editor. (in goal ‘Runner’ from mission ‘Runner’)

i’m a newbie , not so good with the dart ideas , i do not see any error on my POV