The emulator should load the subchannels with the default plugin automatically along with the image if the file containing the subchannel data has the same name as the image (+.sbi name extension).
If it did load the sbi file it should print a line in console mentioning it.
What format does your image have? bin/cue should support subchannels, iso doesn't as far as I know (not sure about other formats).
Did you extract the subchannel data yourself? If yes try one from redump.org, the ones there should definitely work (just make sure you get the correct one, if you are unsure you can always compare the hashes of the image).
If it did load the sbi file it should print a line in console mentioning it.
What format does your image have? bin/cue should support subchannels, iso doesn't as far as I know (not sure about other formats).
Did you extract the subchannel data yourself? If yes try one from redump.org, the ones there should definitely work (just make sure you get the correct one, if you are unsure you can always compare the hashes of the image).