How to hardwire two Ring Doorbells (Version 1 or 2) in a setup without pre-existing doorbell

Hi all. I already hardwired one Ring Doorbell to a plug-in transformer + resistor as described in Ring help. I want to wire a second Ring Doorbell and I'm looking for wiring advice or a diagram. Do I need a separate transformer and resistor or can I run the second Ring off the same transformer - and if so, do I need a second resistor? Anyone have advice or a wiring diagram?