AOV API example not working

Hi everyone,
I'm trying to use this example code provided for Unity 2021.2 and HDRP 12.1 to export albedo images from the script.
https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@12.1/manual/AOVs.html
Unfortunately, it's not working at all for me. The effect that I'm obtaining is that the callback it's never called by the AOVRequestBuilder. I'm not receiving any error in the log so I don't know what is happening. I tried also to switch Unity version and it looks the same.

I know that AOV is usable also from Unity recorder but I need to have an higher color depth and by default Unity Recorder outputs only at 8-bit per channel.
Can anyone help me debugging this problem?