Hi there,

Sorry for the late reply, you may be sorted by now anyway, but I thought I'd share our experience.  After much trial and error with the entries in the Site Url, Base Folder and File Path boxes, we got the following to work.

Site Url:

https://yoursite.sharepoint.com/sites/SiteName_GovServiceFileUpload/

Base Folder:

TestDocuments

File Path
Parking/{case_ref}

Upload Field Token
{fileUpload}

You should then find that the integration will create a folder "on the fly" within the Parking folder with the case ref as the name, and put any associated documents in that folder.  

e.g. if you paste something like this into your browser, you'll see all the associate files for the case

https://yoursite.sharepoint.com/sites/SiteName_GovServiceFileUpload/TestDocuments/Parking/FS-Case-376358626

From what I can recall, you had to be incredibly careful to specify (or not to specify) the / at the end of each folder,