Ring wired doorbell through Friedland 4 chime

Hello I'd be really grateful for advice on which two terminals to wire my bypass jumper into on this chime. There is 12V across the top two (0 and 1), and 12V across the bottom two (2 and 3). I assume it's 2 and 3? I was expecting two wires to be wired to the same terminal, so am a bit confused as to why all four wires are in. The chime isn't working at the moment, but there is 12V at the doorbell. Many thanks