How to return the GUID of a document, one that would be used as "sourcedoc" in a link to the file?

[JimJiraffe]

I have legacy code that relies on returning the GUID of a document I uploaded using MS Graph SDK in my c# asp.net core (6) app.

I can't for the life of me determine how to obtain this value! It's apparent in the ctag and etag fields, but not exact.

When I expand "listitem" in returning a drive item (or even a list item) I don't get anything useful. The guid is just ... missing.

I don't want to rely on the weburl field because my legacy code constructs the URL to load the document, and storing the full web url for every document is time consuming, and it seems wasteful to have to retrieve the weburl from the api on demand so ... I'd really like to use the GUID like I have been doing.

Thanks for any suggestions!!
Jim