downlaod func

  Future<void> download2(String url, String savePath) async {
    var per = await Permission.storage.request();

    if (per.isGranted) {
      toogleisDownloading();
      try {
        Response response = await Dio().get(
          url,
          onReceiveProgress: (received, total) {
            showDownloadProgress(received, total);
          },
          //Received data with List<int>
          options: Options(
              responseType: ResponseType.bytes,
              followRedirects: false,
              validateStatus: (status) {
                return status < 500;
              }),
        );
        // print(response.headers);
        File file = File(savePath);
        var raf = file.openSync(mode: FileMode.write);
        // response.data is List<int> type
        raf.writeFromSync(response.data);
        await raf.close();
      } catch (e) {
        errMsg = e;
      }

      toogleisDownloading();
      notifyListeners();
    } else {
      errMsg =
          "we need Storage permission to download subtitles to your device ...";
      notifyListeners();
    }
  }