I am using PROXMOX 7.1-8 on HP ProDesk 600 G3 with i7-6700 Intel Procesor
After installation I enabled Virtualization options: VT-x VT-d in BIOS,
I follow steps from https://www.reddit.com/r/homelab/comments/b5xpua/the_ultimate_beginners_guide_to_gpu_passthrough/
...Grub, Modules, remapping...