It's been more than five years since I retired and I really don't recall if MSFT maintains per-machine information on their volume licensing. But you may find the information in the "Description" property of the object returned by this:
Get-CimInstance -ClassName SoftwareLicensingProduct
It's going to return a LOT of data (every licensed product on the machine!) so you may want to pipe the results into a where-object {$.description -like "*Windows(R)*" -and $.licensestatus -ne 0}.
After that, I'm not sure of which property might hold the data you're after. Maybe ProductKeyChannel?
You can also try this to see if the information it retrieves might be useful in looking through the properties: how-determine-if-license-oem-retail-volume-windows-10