Monitors connected to SPDIF (RCA Style)

I have SPDF cables and have tried working in the MR Editor and have been trying to get the monitors to work to no avail. Can someone give me a hand and help me understand how to get my monitors working SPDF output connections with the MR816X?

Thanks in advance,

open Mr816s control panel go to MR816 tab
in setting section there is dropdwon menu"Digital I\O,external FX"
choose either"Adat(1-6)+Spdif" or spdif+spdif

then choose in your daw spdif for output