Hi,
By reviewing your concern, I understand that you want to get the metrics for the Manager account via API. Kindly note that the
reporting can only be made on a Google Ads client account and not on an MCC account. You can only get the
Account Hierarchy in the MCC level.
Also, I would recommend that you refer to this
guide to know how zero metrics are handled under different reporting conditions.
Hope this helps. If you have any more queries, please feel free to get back to us.