How to run Amplify's uploadFile function within a dart isolate?

Question

My application has a function that allows to upload videos and other large files to Amazon S3 buckets via Amplify storage. The below function works as expected and uploads a file to my S3 bucket:

  Future<String> uploadFile({File? file, String path = "", String fileName = "", String fileExtension = ""}) async {
try {
  final key = path+fileName+'.'+fileExtension;
  final result = await Amplify.Storage.uploadFile(
    local: file!,
    key: key,
  );
  return result.key;
} catch (e) {
  throw e;
} }

However, given the size of some of these files, the time required to upload can be large and I want to avoid that my users have to wait until the file is completely uploaded. Therefore I want to run the above function in a dart Isolate, so that the file can continue uploading while my user Navigates to different screens of the app.

I tried to achieve this with the below function:

  static uploadFileIsolate(List<dynamic> args) async {
try {
  SendPort responsePort = args[0];
  File file = args[1];
  String path = args[2];
  String fileName = args[3];
  String fileExtension = args[4];
  final key = path+fileName+'.'+fileExtension;

  final result = await Amplify.Storage.uploadFile(
    local: file,
    key: key,
  );
  Isolate.exit(responsePort, result);


} catch (e) {
  throw e;
} }

Which I call like this from my main function:

        final p = ReceivePort();
        Isolate.spawn(uploadFileIsolate, [p.sendPort, file, path, fileName, fileExtension]);

This is not working and throws the below error:

[VERBOSE-2:dart_isolate.cc(1111)] Unhandled exception:
RangeError (index): Invalid value: Valid value range is empty: 0
#0      DatabaseService.uploadFileIsolate (package:mastory/services/database_service.dart:202:7)
#1      _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:300:17)
#2      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:192:12)

After reading this issue it makes me think that the error comes from the fact that Amplify is not configured in the 'isolated' environment.

So my question is: How can I make Amplify's uploadFile function work in an Isolate?

Or, if that is not possible, how can I make sure that the uploadFile function continues until completion while allowing my user to Navigate to other screens in my app?