How can I resolve "The argument type 'Object?' can't be assigned to the parameter type 'String'"?

I wanted to put images which were in assets folder but this error happens repeatly:
The argument type ‘Object?’ can’t be assigned to the parameter type ‘String’.

this is my product.dart:

class Product {
  final String title, description;
  final List<String> images;
  final double rating, price;
  final bool isFavourite, isPopular;

  Product(
      {required this.images,
      this.rating = 0.0,
      this.isFavourite = false,
      this.isPopular = false,
      required this.title,
      required this.price,
      required this.description});
}

List<Product> demoProducts = [~...

and this is main code:

import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import '../../../models/Product.dart';

class ItemListPage extends StatefulWidget {
  const ItemListPage({super.key});

  @override
  State<ItemListPage> createState() => _ItemListPageState();
}

class _ItemListPageState extends State<ItemListPage> {
  final NumberFormat numberFormat = NumberFormat('###,###,###,###');
  List<Product> productList = [
    Product(
        images: ["assets/images/abocado.png"],
        title: "1",
        price: 5000,
        description: 'description',
        rating: 3.5,
        isFavourite: false,
        isPopular: true),
    Product(
        images: ["assets/images/abocado.png"],
        title: "2",
        price: 5000,
        description: 'description',
        rating: 3.5,
        isFavourite: false,
        isPopular: true),
    Product(
        images: ["assets/images/abocado.png"],
        title: "3",
        price: 5000,
        description: 'description',
        rating: 3.5,
        isFavourite: false,
        isPopular: false),
    Product(
        images: ["assets/images/abocado.png"],
        title: "4",
        price: 5000,
        description: 'description',
        rating: 3.5,
        isFavourite: false,
        isPopular: false),
    Product(
        images: ["assets/images/abocado.png"],
        title: "5",
        price: 5000,
        description: 'description',
        rating: 3.5,
        isFavourite: false,
        isPopular: false),
    Product(
        images: ["assets/images/abocado.png"],
        title: "6",
        price: 5000,
        description: 'description',
        rating: 3.5,
        isFavourite: false,
        isPopular: false),
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("product lists"),
        centerTitle: true,
      ),
      body: GridView.builder(
        itemCount: productList.length,
        gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
          childAspectRatio: 0.9,
          crossAxisCount: 2,
          // mainAxisExtent: 250,
        ),
        itemBuilder: (context, index) {
          return productContainer(
              productName: productList[index].title ?? "",
              productImageUrl: productList[index].images ?? "", // error happens here 
              price: productList[index].price ?? 0);
        },
      ),
    );
  }

At first i thought this error occurs because of ‘final List images;‘ in Product.dart but couldn’t solve the problem by changing it’s definition into dynamic.
Anyone can help will be much appriciate

>Solution :

The images property is a list, so you need to take the element instead of directly passing it to an argument that supposedly expects a string:

itemBuilder: (context, index) {
          return productContainer(
              productName: productList[index].title ?? "",
              productImageUrl: productList[index].images?.firstOrNull ?? "", // takes the first element 
              price: productList[index].price ?? 0);
        },