Hi @Moy
The post that you quoted is for people upgrading to Ubuntu Jammy.
Which means they already had HQP Embedded installed on Ubuntu Focal, so there wasn’t many steps required.
To install from scratch is more involved 
These are from my notes I saved. After you install Ubuntu Jammy:
sudo apt-get -y update
sudo apt-get -y dist-upgrade
sudo apt install -f ; sudo apt autoremove --purge ; sudo apt clean
sudo apt-get install linux-lowlatency-hwe-22.04
reboot
sudo apt-get install alsa-utils
wget https://www.sonarnerd.net/src/focal/libgmpris_2.2.1-8_amd64.deb
sudo dpkg -i libgmpris_2.2.1-8_amd64.deb
sudo wget https://www.signalyst.eu/bins/hqplayerd/jammy/hqplayerd_4.32.5-143avx2_amd64.deb
sudo dpkg -i hqplayerd_4.32.5-143avx2_amd64.deb
sudo systemctl restart hqplayerd
sudo apt install -f
You can also install Roon Server on same machine.