"JD-VCC" (without the jumper) goes to the 5V powering the relays.
I don't see a separated screw terminal labeled "JD-Vcc" so the way I see it , to have opto-isolation, the jumper must be removed
and a female jumper plugged onto the JD-Vcc pin which you would connect to your Relay Vcc in order to have an isolated relay Vcc. Is that correct ?