How to pick files or Images from PC or Gallery using universal_io package for flutter web?

Question

Is there any GraphDeveloper?...I am working on a project and got stuck on a problem that when i user dart:io package I open picker = ImagePicker(); images get displayed on web with uint8List inside the ListView.builder. But when i try to upload them to server by using GraphQL_API. I get an error that Error: Unsupported Operation: _namespace. I tried some #stackOverFlow searches and found a package universal_io. but when I used this package this didn't even picked any image or file nor gave me some error telling that if its possible or not. When I searched about the above error i got a point that dart:io sometimes does not support some of features on Flutter_web. here I am attaching my Code.

This is my imagePickerCode

final picker = ImagePicker();

  List<File> images = [];
  
  List<int> imageFiles = [];
 
  List<Uint8List> webImage =[];
  List<Uint8List> uint8Files =[];
  List<XFile>? xFiless = [];


  void _imgFromGallery() async {
    List<XFile>? files = await picker.pickMultiImage(
      imageQuality: 50,
    );
    print("pickedFile: ${files}");

    if (files != null) {
      for (var element in files) {
        setState(() {
          xFiless?.add(element);
          print("X_instances: $xFiless");
          images.add(File(element.name));
          uint8Files = webImage;
          print("FilePath: ${File(element.name)}");
        });
        webImage.add(await element.readAsBytes());


      }
     
    }
  }
  String uint8ListTob64(Uint8List uint8list) {
    String base64String = base64Encode(uint8list);
    String header = "data:image/jpeg;base64,";
    // print("${header} ::${base64String}");
    return header + base64String;
  }

This is my UploadImageMethod()

Future<void> uploadImage(File image) async {
    int responseId = await UploadImages.multipartApi(File(image.toString()));
    if(responseId != 0){
      imageFiles.add(responseId);
      print("ImageFile List= ${imageFiles.toString()}");
    }
    
  }

This is my API CAll

static Future<int> multipartApi(File file)async {
    print("image_file_path=${file.path}");
    var byteData = file.readAsBytesSync();
    print("byteData: $byteData");
    var multipartFile = MultipartFile.fromBytes(
      "",
      byteData,
      filename: "${DateTime.now().second}.jpeg",
      contentType: MediaType("image", "jpeg"),
    );

here i am making the actual task

Future<void> addTransaction() async {
    FocusScope.of(context).unfocus();
    UIHelper.apiCallingAlert(context);
    List imageIds = [];
    
      for (var element in images) {
        String elementPath = element.path;
        print("element: ${elementPath}");
        await uploadImage(element);
      }

after all doing this stuff i get some Blob errors.