https://stackoverflow.com/a/51613332/4880243 problem

main.dart

import 'dart:typed_data';

void main() {
  String source = 'Błonie';
  
  List<int> list = source.codeUnits;
  Uint8List bytes = Uint8List.fromList(list);
  String outcome = String.fromCharCodes(bytes);

  print(outcome);
}