How to Pass Map From Child to Parent Flutter

So, I am taking an example from Flutter documentation. Actually, it is working fine but I just want to customize it by passing the result (Map) to parent

import 'package:flutter/material.dart';

void main() {
  runApp(
    const MaterialApp(
      title: 'Returning Data',
      home: HomeScreen(),
    ),
  );
}

class HomeScreen extends StatefulWidget {
  const HomeScreen({Key? key}) : super(key: key);

  @override
  State<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  Map AdList = {};
  callback(AdListNew){
    setState(() {
      AdList = AdListNew; ////// 1. WANT TO UPDATE THE LIST WITH NEW MAP FROM CHILD ////
    });
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Returning Data Demo'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text('This text is'),
            SelectionButton(AdList,callback),
          ],
        ),
      ),
    );
  }
}

class SelectionButton extends StatefulWidget {
  Map AdList;
  Function(String) callback;

  SelectionButton(this.AdList,this.callback);
  @override
  State<SelectionButton> createState() => _SelectionButtonState();
}

class _SelectionButtonState extends State<SelectionButton> {
  String show = 'Pick me';
  @override
  Widget build(BuildContext context) {
    return ElevatedButton(
      onPressed: (){
        NavigateAndDisplay(context);
      },
      child: Text(show),
    );
  }

  void NavigateAndDisplay(BuildContext context) async{
    final result = await Navigator.push(
      context,
      MaterialPageRoute(builder: (context) => const SelectionScreen()),
    );
    // After the Selection Screen returns a result, hide any previous snackbars
    // and show the new result.
    setState(() {
      show = result;
    });
    Map AdListNew = {
      'text':result,
    };
    widget.callback(AdListNew); //// 2. PASS MAP TO PARENT ////
  }
}

Here is an error that I got

lib/main.dart:80:21: Error: The argument type 'Map<dynamic, dynamic>' can't be assigned to the parameter type 'String'.

• 'Map' is from 'dart:core'. widget.callback(AdListNew); ^

I really appreciate any answers. Thank you