This error may appear if you try to add a base / table from another Airtable account without updating the Airtable API Key linked to your Bannerbear account.
Ensure that you have the correct Airtable API Key for the base / table you want to use. Check out Where do I find my airtable API key? for more info on how to update.
If you are still having trouble after updating, don't hesitate to contact our Customer Support ↗.