def METHOD_NAME(parent_id: Optional[str] = None,
                                           opts: Optional[pulumi.InvokeOptions] = None) -> AwaitableGetOrganizationalUnitChildAccountsResult:
    """
    Get all direct child accounts under a parent organizational unit. This only provides immediate children, not all children.
    ## Example Usage
    ```python
    import pulumi
    import pulumi_aws as aws
    org = aws.organizations.get_organization()
    accounts = aws.organizations.get_organizational_unit_child_accounts(parent_id=org.roots[0].id)
    ```
    :param str parent_id: The parent ID of the accounts.
    """
    __args__ = dict()
    __args__['parentId'] = parent_id
    opts = pulumi.InvokeOptions.merge(_utilities.get_invoke_opts_defaults(), opts)
    __ret__ = pulumi.runtime.invoke('aws:organizations/getOrganizationalUnitChildAccounts:getOrganizationalUnitChildAccounts', __args__, opts=opts, typ=GetOrganizationalUnitChildAccountsResult).value
    return AwaitableGetOrganizationalUnitChildAccountsResult(
        accounts=pulumi.get(__ret__, 'accounts'),
        id=pulumi.get(__ret__, 'id'),
        parent_id=pulumi.get(__ret__, 'parent_id'))