How to use an extended floating action button in Flutter

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp();

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Extended FAB Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.deepPurple,
      ),
      home: const MyHomePage(title: 'Extended FAB Demo Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({this.title});
  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  bool showOptions = false;
  List<String> items = [];

  void toggleOptions() {
    setState(() {
      showOptions = !showOptions;
    });
  }

  void addItem() {
    setState(() {
      items.add('Item ${items.length + 1}');
    });
  }

  void deleteItem() {
    setState(() {
      if (items.isNotEmpty) {
        items.removeLast();
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: ListView.builder(
        itemCount: items.length,
        itemBuilder: (context, index) {
          return Container(
            margin: EdgeInsets.symmetric(vertical: 4.0, horizontal: 8.0),
            decoration: BoxDecoration(
              color: Colors.blue.shade50,
              borderRadius: BorderRadius.circular(8.0),
              boxShadow: [
                BoxShadow(
                  color: Colors.grey.withOpacity(0.5),
                  spreadRadius: 1,
                  blurRadius: 2,
                  offset: Offset(0, 1), // changes position of shadow
                ),
              ],
            ),
            child: ListTile(
              leading: CircleAvatar(
                child: Text(
                  items[index][0],
                  style: TextStyle(color: Colors.white),
                ),
                backgroundColor: Colors.blue,
              ),
              title: Text(
                items[index],
                style: TextStyle(fontSize: 18.0, fontWeight: FontWeight.w500),
              ),
              trailing: IconButton(
                icon: Icon(Icons.delete, color: Colors.red),
                onPressed: () {
                  setState(() {
                    items.removeAt(index);
                  });
                },
              ),
            ),
          );
        },
      ),
      floatingActionButton: Column(
        mainAxisAlignment: MainAxisAlignment.end,
        children: [
          FloatingActionButton.extended(
            onPressed: toggleOptions,
            label: Text('Extended FAB'),
            icon: Icon(Icons.add_alert),
            backgroundColor: Colors.deepPurple,
          ),
          SizedBox(height: 16.0),
          Visibility(
            visible: showOptions,
            child: Column(
              children: [
                FloatingActionButton(
                  onPressed: addItem,
                  tooltip: 'Add Item',
                  child: Icon(Icons.add_alert_outlined),
                ),
                SizedBox(height: 16.0),
                FloatingActionButton(
                  onPressed: deleteItem,
                  tooltip: 'Delete Last Item',
                  child: Icon(Icons.delete_rounded),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}