You need a service account in order to access Google APIs. A service account is an account that belongs to an application, such as Etlworks Integrator, instead of to an individual end user. The application calls Google APIs on behalf of the service account, so users 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 in which user consent is sometimes required.)
a service account is not the same as an account used to log into Google services from a web browser.
Read more about Google Service accounts.
Integrator already has a service account which can be used to access Google APIs. This account is linked to the email address
email@example.com. You can create you own account (see step-by-step instructions below) if you prefer to use your own, instead of the default.