async def update_through_instance(self, child: "T", **kwargs: Any) -> None:
        """
        Updates a through model instance in the database for m2m relations.

        :param kwargs: dict of additional keyword arguments for through instance
        :type kwargs: Any
        :param child: child model instance
        :type child: Model
        """
        model_cls = self.relation.through
        owner_column = self.related_field.default_target_field_name()  # type: ignore
        child_column = self.related_field.default_source_field_name()  # type: ignore
        rel_kwargs = {owner_column: self._owner.pk, child_column: child.pk}
        through_model = await model_cls.objects.get(**rel_kwargs)
        await through_model.update(**kwargs)

        Updates a through model instance in the database for m2m relations.

        :param kwargs: dict of additional keyword arguments for through instance
        :type kwargs: Any
        :param child: child model instance
        :type child: Model
        
ormar/relations/querysetproxy.py