I used the guide to setup Headless Plexamp with OdinB’s script [https://howtohifi.com/how-to-create-a-headless-plexamp-player-using-odinbs-plexamp-installer-script/] with success. I have tried this guide here to get Plexamp to auto start on restart of Headless Plexamp with no success. I still have to enter Node js script [node plexamp/js/index.js] then it will start up and work as intended. Below is some information that may be helpful if someone is willing to help me.
Username: pi Node JS version: 20 Plexamp Version: 4.11.5 Raspberry Pi Zero 2W with latest version of Raspberry Pi OS Lite 64 Innomaker Hifi DAC Mini [works flawlessly with their guide to add to Pi OS audio out.]