getting AuthenticationError.NOT_ADS_USER using service accounts.

[Testing ForAds]

Hi Team,

My goal is to integrate the ad words api, using service accounts.

> Previously I used Oauth authentication to integrate the ad words api, I able to perform the all services using this, but the the problem is while generating the refresh token I'm getting the google authentication pop-up at every time. So, I moved to service accounts, to avoid the human authentication.

1)  I created a service accounts, and enabled the gsuite domain delegation by clicking on the checkbox.

2) 3) I created a G-suite account (free trial for 14 days), but it is not verified, anyway I'm giving authorization to service account by providing the client Id and scope in Manage Client API Access.

Please help me to fix this error.

Thanks guys.