Equally to the RPi Port option, I assume you must have followed some guide somewhere on setting up the OS to enable the serial port through the GPIO pins? It won't work out of the box, and requires some extra configuration first.
Hello Charlie. Many thanks for the reply.
Yes, indeed. I followed many online tuits, of which was a total mine field. Some referred to the Pi Zero W and some to the new Pi Zero 2 W. Then, i had a total nightmare trying to find the right OctoPi iso. I have now reached the point where the Raspberry Pi / OctoPi will run but as you quite rightly pointed out, it does not run "out of the box". Any help from here on in would be greatly appreciated. I can SSH into the Pi so that is an achievement.