async def delete_through_instance(self, child: "T") -> None:
        """
        Removes through model instance from the database for m2m relations.

        :param child: child model instance
        :type child: Model
        """
        queryset = ormar.QuerySet(model_cls=self.relation.through)  # type: ignore
        owner_column = self.related_field.default_target_field_name()  # type: ignore
        child_column = self.related_field.default_source_field_name()  # type: ignore
        kwargs = {owner_column: self._owner, child_column: child}
        link_instance = await queryset.filter(**kwargs).get()  # type: ignore
        await link_instance.delete()

        Removes through model instance from the database for m2m relations.

        :param child: child model instance
        :type child: Model
        
ormar/relations/querysetproxy.py