Currently ExpanDrive Server edition only listens on localhost, as it is not currently designed to be a hardened service exposed to the public internet. Additionally, cloud storage providers like Google, Dropbox, Box, Microsoft all require the OAuth flow to have a well-known redirect URL to land on with an authorization code at the end of the OAuth flow. Since localhost is the only well-known URL each machine shares, the redirect must land there. Using the port forwarding solution described above, you can redirect to your local machine and have the result captured by ExpanDrive running on your server.