Before you begin, you need to make sure you have already done the following in your Google Cloud:
Then you can create your BigQuery data source using your service account key.
First, you need to specify your BigQuery project ID and upload your service account key into
JSON Key File. If you want to preview the dataset schema in query source page, you need to check
Load Schemaoption. If your dataset is outside of the US, you need to specify the
Processing Location, eg. europe-west1. You can find your region name to use from this document.