Find all externally shared files and folders

I am trying to list all externally shared files and folders from a specific SharePoint site, regardless of sensitivity. Basically, everything that is shared outside of the organisation.

I tried the audit log, but it shows only recent history and matching share and unshare/delete events is cumbersome. eDiscovery seems very slow and I cannot make an alert out of it.

At last, I tried to create a DLP policy, which looked good because I could set up alerting, but then I had to select "Sensitive info types". I do not want to filter on sensitive info, I need all files and folders.

Is it possible to just list all externally shared files and folders with the help of Microsoft Compliance?