The "PVP" is in the code, if you install the scripts into the game as directed, set up the server with MySQL, then in an event add a script saying
It will enable you to Login,Register, or cancel.
After Registering and Logging in you may either logout, trade with another person
SIGNED ON IN YOUR SERVER, or battle another person
SIGNED ON IN YOUR SERVER If you had read the explanation or looked around the code you would know this. There are a few bugs in the system, I fixed one or two of them, and he has them fixed for whenever he decides to update it.
No links required. It's all in the download that's on the first post.
It was all provided, all you had to do was look and learn.