Service Account NOT_ADS_USER error

[IMM Boulder]

I have logged in with the administrator login and created a service account and am using the p12 key to generate an access_token for access to the api and when I try to use the access_token I get the error:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><reportDownloadError><ApiError><type>AuthenticationError.NOT_ADS_USER</type><trigger>&lt;null&gt;</trigger><fieldPath></fieldPath></ApiError></reportDownloadError>

Is there something that I am missing?

[IMM Boulder]

I have verified that clientCustomerId is in the header and that the user is an adwords user.

[Anash P. Oommen (AdWords API Team)]

Hi,

Did you set the prn email when getting the access token in service account flow? This field is required, since AdWords API doesn't allow anonymous OAuth2 access.

Cheers,
Anash P. Oommen,
AdWords API Advisor.