Service account impersonation

Hi!

I was trying to request the dv360 API with an impersonated service account token.
Hi guys,

running into the same issue.
When I try to request an impersonated token like this :
return new google.auth.GoogleAuth({
keyFile: './google-credentials.json',
clientOptions: {
subject:
'test-service-account-to-impers@some-domain', //serviceAccountEmail,
},
scopes: SCOPES,
});

where const SCOPES = [
'https://www.googleapis.com/auth/display-video',
'https://www.googleapis.com/auth/display-video-mediaplanning',
'https://www.googleapis.com/auth/display-video-user-management',
'https://www.googleapis.com/auth/doubleclickbidmanager',
];

But i receive an error from the API: Error: unauthorized_client: Client is unauthorized to retrieve access tokens using this method, or client not authorized for any of the scopes requested

if I remove the clientOptions I receive the token and can get to the API.

Note: roles added to the master service account got from here https://cloud.google.com/iam/docs/impersonating-service-accounts#iam-service-accounts-grant-role-sa-console