Click on the “Export External Scans (CSV)” link at the bottom of the dashboard to export a CSV of the external scans findings.
In the next pop up you should be able to select the timeframes of the external scans that you would like to download in the CSV. If no such selection is made, the CSV will contain findings from all the external scans in your account.
The downloaded CSV contains the grades for all the sections and top 10 findings from each section (apart from other metadata like last scan time etc).