Did you check/read the manual? Chapter 21.3: "The optical input automatically switches to SPDIF operation when such a signal is detected. The audio information is then shown in TotalMix on the first two ADAT channels ADAT 1/2, which are channels 13 and 14."
Regarding clock synch. TV will act as clock master (no other way) and sends the clock signal through its digital output. The UCX II needs to be configured as "slave" to read clock from the optical input (driver settings, clock source = "ADAT").
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14