Hello Tomas,
While working with Google Ads API, the login-customer-id you are defining in the API call should be the manager account of the clientCustomerID from which you are pulling the data. Also, the user making the API call should have access to the log-in-customer-id. Please double check, if you are still facing the issue, you could share login-customer-id, client-customer-id and email address of the user with me using
reply privately to the author option.
Regards,
Sai Teja, Google Ads API Team

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