downloadBytes function
The non-web stub of downloadBytes: there is no browser to download into, so it fails clearly. The real implementation ships only in a web build.
Implementation
void downloadBytes(Uint8List bytes, {required String filename, String mimeType = 'video/mp4'}) {
throw UnsupportedError(
'downloadBytes is only available in the browser; got a request to download '
'"$filename".',
);
}