Can not add Box2D in processing

I was reading The Nature of Code ( the book written by Mr. Daniel Shifman). There I found the chapter which contains physics libraries. I wanted to add Box2D (the processing version of Box2D) to my processing.

I downloaded the library for pbox2d from this link - https://github.com/shiffman/Box2D-for-Processing . And then I added it to processing.

But when I implemented some code from nature of code it did not work. For example processing was saying that there is nothing as PBox2D.

Please help me. Thanks in advance

assuming you use
Processing IDE 3.5.3 can load library:

Thanks a lot. It worked fine…