This guide is for installing Home Assistant Supervised using Debian 12 on a bare metal machine but not for running HA Supervised on Proxmox.
A little search would have brought you to i.e.
-
Installing Home Assistant OS using Proxmox 8
or to i.e. -
How To Install Home Assistant on Proxmox: The Easy Way
or to i.e - How to Install Home Assistant on Proxmox
and so many more… 