Credentials

Use Service Account JSON when scheduled imports should not depend on a personal Google account.

Steps:

1. Create a Google Cloud service account.
2. Create and download a JSON key for it.
3. Share the spreadsheet with the service account email.
4. Paste the service account JSON key into Service Account Key (JSON).

The service account email is the client_email value inside the downloaded JSON key.

Viewer access is enough for importing sheet data because the source connector only reads the sheet.