Here’s my take on “is the way”
Prior to Section 1, you will want to ensure UEFI Boot & Virtualisation is enabled and Secure Boot is disabled in the bios of your machine.
Section 1 - Use this guide
Section 2 - Use Proxmox VE 7 Post Install script*
Section 3 - Use Home Assistant OS VM script*
*Always remember to use due diligence when sourcing scripts and automation tasks from third-party sites.
Enjoy