line output

what settings do i need to get a line output? i’m running an optical cable to my monitors and am able to hear my mixes… but, i cannot get anything to come out of the line outputs…

i troubleshot everything!

-the input on my outboard effects works
-the cable (which is connecting the output of the ur824 to the input of the outboard effect) also works
-the line output of the steinberg works too

this is really weird. i don’t think i’m able to get a good line output signal into my outboard effect. maybe i’m not using the right cable… 1/4" is what i got