Missing Asset Folder

Hello, I'm following along in the Unity and Oculus VR development series. I got to Chapter 3 step 4 and noticed I'm missing the VRTK folder in my assets folder. I went back and rewatched all of the prior steps and don't see any instructions on how to obtain that folder. Can someone help me? I can't move on until I figure out why I'm missing that folder. This folder has prefabs that are vital to getting Oculus integration and VRTK to work together. Thanks in advance!