Go to https://rpxnow.com/ and sign-in. In the left navigation bar there is a tab for each of those providers which includes instructions for setting up each one. All three require you to obtain an API key and secret for your individual site, and approve their developer terms of service.
Send as much information about your php/wordpress version and runtime as you can to brian -at- janrain.com. We'll do our best to get the plugin working with your configuration.
Note: using a modern version of PHP and Wordpress usually fixes most problems, so make sure you are up to date.




