You need a service account in order to access some of the Google APIs. A service account is an account that belongs to an application, such as the Etlworks Integrator, instead of to an individual end-user. The application calls Google APIs on behalf of the service account, so you aren't directly involved. This scenario is sometimes called two-legged OAuth or 2LO (the related term "three-legged OAuth" refers to scenarios in which the application calls Google APIs on behalf of end-users, and the user's consent is sometimes required).
A service account is not the same as an account used to log in to Google services from a web browser.
Read more about Google Service accounts.
The Etlworks Integrator already has a service account that can be used to access Google APIs. This account is linked to the email address:
You can create your own service account if you prefer to use your own, instead of the default.