To connect this hub to your Google account, you need a free Google Cloud project. It takes about 5 minutes:
Go to console.cloud.google.com and create a new project (call it whatever, e.g. "Atrium").
In APIs & Services → Library, enable: Google Classroom API, Google Calendar API, Gmail API, Google Drive API, Google Tasks API.
In APIs & Services → OAuth consent screen, set up an "External" app, add yourself as a test user.
In Credentials, create an API Key and an OAuth 2.0 Client ID (type: Web application). Add your site URL to "Authorized JavaScript origins" (e.g. http://localhost or your Cloudflare Pages URL).