NetDocuments does not provide public documentation for Oauth application configuration.
For NetDocuments customers, contact NetDocuments support to be provided a setup guide or other guidance.
Oauth application configuration can be initiated at support.netdocuments.com/s/developed-applications - note that this is the NetDocuments support portal, which is a different login than standard NetDocuments.
Use the redirect URL of https://app.trycaddi.com/oauth-callback