We will need access to your BigQuery, which will serve as the repository for your SegmentStream project.
Below are the steps that explain how to provide the necessary project access:
Open your SegmentStream project.
Navigate to Settings → BigQuery, and copy the service account email.
Go to the Google Cloud Platform Console.
Open the console left side menu and click IAM & admin. Select IAM from the list.
Click GRANT ACCESS:
Paste the service account email address into New principals field.
Select the BigQuery Data Editor and BigQuery User roles.
Click Save.
Return to your SegmentStream project and navigate to Settings → BigQuery.
Check access by clicking the TEST AND CONNECT BIGQUERY button.
You can now follow the BigQuery guide to complete the connection - Complete Connection