The type or namespace name 'LWRP' does not exist 

Hi
Trying to open the project using Unity 2018.3.7f1 and LWRP 4.8.0-preview.

Am getting several compile errors all relating to a  missing LWRP package
ie
using UnityEngine.Rendering.LWRP;
using UnityEngine.Experimental.Rendering.LWRP;