Cannot resolve symbol 'PostProcessing'

In IDE:

using UnityEngine.Rendering.PostProcessing;

Gives me this error =>
error CS0234: The type or namespace name ‘PostProcessing’ does not exist in the namespace ‘UnityEngine.Rendering’ (are you missing an assembly reference?)

Based on the latest docs this is the correct namespace.

I already have a global volume object in my scenes and it works and I have URP asset so is this a bug? Or am I missing something? I have no issues on older Unity Versions. And I have run into other bugs with 2021.3.8 that are reported as fixed in newer versions so unsure if I forgot something in setup or if this is a bug.

Well the error was entirely correct, the namespace did not exist because I did not have the post-processing package installed in this project. My dumb self must have lost it in a crash or git restore when I had originally set it up.