Security Settings to use SmartCloud Outlook Connector

If anyone is successfully using the SmartCloud Outlook Connector add-in, can you tell me if and what any security settings may be required from within bpm'online to facilitate a successful connection?  I have successfully installed the plug-in into Outlook and I'm able to open a message and launch the add-in, which brings me to a login screen for bpm'online.  I type my username, password and instance URL (have double, triple, quadruple tested it), but as soon as I hit the "Sign in to my BPM'Online account", it returns a "NotAuthorized" error.

I suspect that perhaps I need to add "Access to object from external sources" permissions -- but if so, to what objects?