I've totally revamped the blog post I wrote in June using Proxmox 8.0 and how to configure it for vGPU with Windows 11 Pro. The new post is fully updated for Proxmox 8.1, re-wrote every section, and added a lot more content driven by user feedback.
Proxmox VE 8.1: Windows 11 vGPU (VT-d) Passthrough with Intel Alder Lake
Proxmox VE 8.1: Windows 11 vGPU (VT-d) Passthrough with Intel Alder Lake