This article is a follow-up to the article describing how to add FCSDK via a VisualForce page to SalesForce:
As a prerequisite you should complete the instructions in this article first. You can then either re-use this page or create a new one.
Either way you'll want to updated your code, within the VF Page editor to look something like this:
However, you'll need to change the IP references to point at your relevant CafeX and Session servers. If you haven't got a session server up and running yet, there is a PHP one attached to the following article:Minimal Application
We'd advise you to work through this article if you are unfamiliar with the FCSDK session provisioning process. Be mindful that you'll also need to update the server IP references witih in your own session server.
Further, within the VF Page code you'll need to load in the JS libraries and post to the session server over https, as this seems to be a requirement from Sales Force. There's also a requirement to add an Access-Control-Allow-Origin header to your session server, which should end up looking something like this:
Once you have the code up and running, you can preview your VF Page Minimal App and place a call to 1001. To receive this call you'll need to be logged into the CSDK Sample app as user 1001.