adloop init walks you through this; here’s the same path for reference.
1
Create a project
console.cloud.google.com → New project. Free; no billing account needed for these APIs.
2
Enable the APIs
Under APIs & Services → Library, enable: Google Ads API, Google Analytics Data API, and Google Analytics Admin API. Optionally, for the corresponding toolsets: Tag Manager API, Search Console API, Merchant API, PageSpeed Insights API.
3
Create OAuth credentials
APIs & Services → Credentials → Create credentials → OAuth client ID, application type Desktop app. Download the JSON; the wizard copies it to
~/.adloop/credentials.json.4
Configure the consent screen
Add yourself as a test user, or publish the app to In production (recommended: tokens for apps left in “Testing” expire every 7 days).