Start by installing the latest version of Unity 6000 from Unity Hub.

in this tutorial I'm using 6000.3.5f2, later versions should work.

Create a new project. I named the project APS_SDK_HDRP.

Search for the templates "High Definition" and select High Definition 3D , this sets up Unity on first launch so the editor is configured for HDRP.

Now you have a empty scene with a Global Volume already added. 

When the project loads you must install HDRP from the package manager.

By default Unity doesn't include the HDRP package. We need to install it from package manager. 

From package manager search for "High Definition Render Pipeline" and install the package.

Download the APS_SDK  and import it into the project.

⚠️Make sure you are using SDK version 10.4.8 or later so it includes the diffusion profiles D1..D5, explained later.

Import the APS_SDK and import it into the project.

Make sure to download version 10.4.8 or later so diffusion profiles are included.

Diffusion Profiles are explained further down.

Install the XR Plugin

Edit > Project Settings > XR Plugin Management > Install XR Plugin Management

This is needed to enable stereo shader compilation. If you build a avatar but forget to install the XR plugin the materials will render only in one eye in VR 

Enable OpenXR

After the XR plugin has finished installing enable the OpenXR checkbox to enable the stereo render mode.

OpenXR Render Mode

Last thing is make sure the render mode is set to Single Pass Instanced:

⚠️ Important Last Step

From the APS_SDK dropdown menu click on Set HDRP Render Pipeline.
This adds the APS_SDK_HDRP define symbol, and enables HDRP build support in all SDK scripts.