Hello, I'm TV Tech1 and I'll be working with you to identify and help you resolve your problem.
It does depend on the model and age of your TV set.
Older TV models didn't pass the HDMI audio over to the TV's optical output, but only allowed either the Tuner or some of the Scart/RCA audio to pass over to the Optical audio connection.
2010 models started passing all inputs over to the optical output, and that's usually the ones you find on all soundbars. Before that, you had to connect the optical and the older RCA audio jacks to the soundbar and switch the soundbar's input setting between the two, depending on what you were watching on TV.
I don't see the older RCA inputs as a second input on your TV set. Did you only get ONE optical input on that model? If so, the TV has to be a lot newer than 2010, and we need the TV's model number to see if that will work with your TV set, and the Blu Ray, and Sky box+ units altogether.
my tv model no is TX-L42B6B
2HDI SKT 1 OPTICAL SKT 1 SCART SKT
DVD - DMP-BD79
STD SKY+ BOX(NOT HD)