I'm trying to create a Google service account which has access to a Drive folder so I can use google-spreadsheets to read and write to files in the folder. During development I created a service account under my unmanaged Google account. The user account has owner access. In order to be allowed access I needed to change the document sharing settings to public (with link access). For development this is no issue, but of course in production I do not want my data to be publicly accessible.
How do I make sure the service account has access to the document while it is not publicly shared (shared within organisation is preferred)? Setting it to organisation access only, the api gives me a 403 (Forbidden) code.