The installation of a supported Proxmox VE server should be done via bare-metal ISO installer. In some cases it makes sense to install Proxmox VE on top of a running Debian Bullseye 64-bit, especially if you want a custom partition layout. For this How-To any official Bullseye installation medium should work.
For this Demo, I am installing 3 KVM VM’s. As you can do VM nesting. Also, you can do this on Vmware or Hyper V. Here is the Architecture.