Hi @Mark Callan ,
Thank you for posting in this community.
To run the report on file and folder sharing in a SharePoint site(SharePoint)
- Open the site where you want to run the report
- On the Settings menu, click Site usage.
- In the Shared with external users section, click Run report.
- Choose a location to save the report, and then click Save.
Report is titled "Shared with external users", but in fact - there are all shares, not only external.
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