code: def confirm(self, batch_id=None, filename=None):
          
          if batch_id or filename:
              export_history = self.history_model.objects.using(self.using).filter(
                  Q(batch_id=batch_id) | Q(filename=filename),
                  sent=True,
                  confirmation_code__isnull=True,
              )
          else:
              export_history = self.history_model.objects.using(self.using).filter(
                  sent=True, confirmation_code__isnull=True
              )
          if export_history.count() == 0:
              raise ConfirmationError(
                  "Nothing to do. No history of sent and unconfirmed files"
              )
          else:
              confirmation_code = ConfirmationCode()
              export_history.update(
                  confirmation_code=confirmation_code.identifier,
                  confirmation_datetime=get_utcnow(),
              )
          return confirmation_code.identifier
docs: Flags the batch as confirmed by updating
          confirmation_datetime on the history model for this batch.