Comment 41 for bug 253422

SPDIF is the optical output. It's often the same physical jack as your
headphone. If any of you know someone with a digital receiver, that's
what you need to test with. If you can connect the digital receiver to
your headphone jack and have it work through the receiver, then it
passes the test.

And yes, you do have SPDIF. It's listed in your outputs.
Went over this a few comments ago.