Without model numbers we can't know what audio outputs the TV has and what input the HTS has.
If both the TV and HTS support HDMI-ARC then the HDMI cable from the HTS goes to the TV HDMI-ARC input. Turn ARC on in the TV menu.
If the TV and HTS both support optical digital audio then connect them with a Toslink cable, Turn the optical output on in the TV menu. You may also have to turn the TV speakers off.
If the TV has a headphone output and the HTS an aux input then use that connection.
If the TV has a digital audio out and the HTS an aux input then you will need a digital to analog converter and cables to connect them.