XF 2.0 How to install addon on Xenforo?

Hello, I upgraded to Xenforo but I can't find the install addon. Is there a folder I can put my addon in to install it to Xenforo?
I followed the exact instruction but it is still not showing up listed as installable or upgradeable. It's an xml file from Postloop. I put it in the library folder. I don't know.