Nbt

Hi All, I am trying to uppload a file using the API and always getting a 404 error. I am trying to do an HTTP POST to https://mdh-p01-api.hornbill.com/<instanceid>/dav/session/filename.csv using the file content on the request body and the API Key on the http headers but I always get a 404 error. Do you know what could be causing this? Thanks Nbt