When you run a Content Search in the Microsoft Purview compliance portal and want to download/export the search results, you must:
Select Export results in the Content Search tool.
Purview generates an Export key.
Use the eDiscovery Export Tool (ClickOnce application) to download the results.
The Export key is required to authenticate the export process.
Certificate # Not used in this process.
Password # Not required for export.
PIN # Not relevant here.
Export Key # # Mandatory to export search results.
# Reference:
Export Content Search results - Microsoft Learn