Hi Ankur,
AdWords API reports can only be generated per client account as discussed here. If what you wish is to retrieve the reports for all client accounts under a specific MCC account, you can refer to the Parallel Report Download example (also available in other languages) as this should allow you to do just that.
As for invoice information, this is currently not supported in the AdWords API. You may continue to follow our blog for updates.
Best regards,
Peter
Google Ads API Team
Hi Bastien,
Thank you for reaching out to Google Ads API Support.
The feature to retrieve invoices is not available in the AdWords API, but it is available in Google Ads API (Beta).
Please refer to the InvoiceService documentation below for more information:
https://developers.google.com/google-ads/api/docs/billing/invoice-service
Hope that this helps your issue, thank you.