hatangFilePicker function
Picks any file with file_picker (13.x) for the chat composer's "File"
option: HatangChat.configure(pickFile: hatangFilePicker).
Implementation
Future<UploadSource?> hatangFilePicker() async {
final f = await FilePicker.pickFile();
if (f == null) return null;
return UploadSource(bytes: await f.readAsBytes(), name: f.name, mimeType: mimeTypeForName(f.name) ?? '');
}