Can't find the location of "+ Source"

I’m working on setting up a virtual studio using the “Vive Mars Cam Track” technology.

The instructions say to “Click + Source, go to Message Bus Source under Live Link Sources, and then click VIVE Live Link to open the Live Link plug-in.”

I’m not seeing where + Source is, I’ve tried looking for Message BUs Source, and Live Link as well, but I can’t seem to find them in Unreal. Am I just missing where this panel or button is located?

In 5.2, Window>VirtualProduction> Livelink.
This should open the livelink window, if you have activated the plugin.
You will see Source + button on the top left of that window.

What I don’t see is what’s inside the “message bus source” nothing there for me…

Solved: My PC Network adapter IP setting was conflicting with IP on Mars unit.