Hi , @t_b_heth as @elan explained … you need to use your PlexAmp player on your phone to select the headless PlexAmp on the raspberry 4… (its an end-point) , you can play music via the web interface of the pi but that would defeat the purpose. If you have configured everything correct music will be played on the PI .
Couple of points, make sure you have used the steps to auto start the headless PlexAmp after a power down (switch off)
