Auto-pull needs a Web OAuth client (your Python one is Desktop-only). One-time setup:

1. Google Cloud Console → APIs & Services → Credentials.
2. Create credentials → OAuth client ID → Web application.
3. Under Authorized JavaScript origins add:
   this site's origin
4. Enable the YouTube Data API v3 and YouTube Analytics API for the project.
5. Copy the Client ID (ends .apps.googleusercontent.com) and paste below.