2 Ring Doorbells (Gen 2), 1 Transformer, No Chime- Need help

I have 2 Ring doorbells (Gen 2) that I am hard wiring to 1 transformer with *no chime.* My questions. 1) How many resistors do I need to add ( 1 or 2) 2) Where would the resistors go in the wire diagram I have seen the ring wired diagrams but there are none that have 2 doorbells and 1 transformer with resistors pictured ( no chime)