CommandBuffer: Temporary render texture _AfterPostProcessTexture not found...

[HardwareHaquer]

I followed along with your install tutorial and the grayscale example. I get the warning above for SetGlobalTexture, SetRenderTarget, and BlitDestination. And the example does not work but there are no errors in console, just warnings. I am using URP 12.1.8.
I have used Unity for a while but this is my first foray into custom post-processing.

To Reproduce
Steps to reproduce the behavior:

1. complete tutorial

Expected behavior
Well, I hoped to see grayscale magic happen before my eyes. :)

Desktop (please complete the following information):

• OS: Mac (Apple Silicon)
• Unity Version 2021.3.16f1
• Version 2.0.0
• URP 12.1.8

Additional context
No additional context just want to say thanks!