API URL – Onfolio

I am trying to publish a folder to my blog using Onfolio, and it asks me for the API URL in custom settings. I have tried a couple things, none of which are working. Apparently several people have done it but are a little light on the details in the Onfolio forums regarding WordPress.

When I used …/xmlrpc.php as the URL I was obviously missing some required parameters. Any insights?

Thanks much.