Hi Dipack,
Thank you for reaching out. You could use the ManagedCustomerService.get() to retrieve the account hierarchy information under a particular Google Ads account. This is a code example for you on how to use this service. Please let us know if you have any further questions.
Thanks and regards,
Xiaoming, Google Ads API Team
Hi Dipack,
Thank you for reaching out. You need to provide the clientCustomerId information in the header to make API calls against this account. If you do not provide the clientCustomerId in the API call, you will not be able to retrieve data from this account and the API call would fail. This is a necessary step. Please let me know if you have any further questions.
Thanks and regards,
Xiaoming, Google Ads API Team