How to Export Data into BigQuery
The newly-created data source has the NOT EXPORTED status.
Select three dots, and then select Set BQ Key.
How to create a service account key.
BQ key is another name for the service account key.
Select Choose file, upload your service account key, and then select Save.
Select Export data.
The data source status will be changed to LOADING.
Open your Google Cloud Platform, and then select BigQuery.
Find your exported data source by the dataset name you used while creating the data source.