can't get image from wordpress rest api in flutter

i want to fetch the image of my products in my flutter app ...

but i cant it show me this weird error and i don't know what is it for?

and this is my code ( exactly based on a tutorial that worked for the teacher) :

class _MyPageState extends State<MyPage> {
  late List<Product>? listproduct;

  @override
  void initState() {
    fetchAllProducts().then((value) => listproduct = value);
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: FutureBuilder(
        future: fetchAllProducts(),
        builder: (context, snapshot) {
          if (snapshot.hasData) {
            return ListView.builder(
              itemCount: listproduct!.length,
              itemBuilder: (context, index) {
                return Card(
                  child: ListTile(
                    title: Text(listproduct![index].name.toString()),
                    subtitle: Text('${listproduct![index].price} تومان'),
                    leading:
                        Image.network(listproduct![index].images!.join(', ')),
                  ),
                );
              },
            );
          } else if (snapshot.hasError) {
            return Text('${snapshot.error}');
          } else {
            return const Center(child: CircularProgressIndicator());
          }
        },
      ),
    );
  }
}