I don’t think a zone player has a pin printed on it, it was made long before that system was initiated. Are there not other instructions on how to connect?

For what it is worth, Sonos pins are printed on the product label on the device, most often affixed to the bottom of the device, although locations do vary slightly, based on the type of speaker, and if there is a ‘bottom’ that makes sense. 

The PIN’s are typically hard to read. On black speakers the PIN’s are printed in small, dark gray type.

I just found it. It's not on the device. I had to go to the sonos website and I was prompted a 5 digit pin so I could connect to my roku. Thanks for your responses!!!!