def default_source_field_name(self) -> str:
        """
        Returns default target model name on through model.
        :return: name of the field
        :rtype: str
        """
        prefix = "to_" if self.self_reference else ""
        return self.through_relation_name or f"{prefix}{self.owner.get_name()}"

        Returns default target model name on through model.
        :return: name of the field
        :rtype: str
        
ormar/fields/foreign_key.py