You can wirelessly connect some soundbars to TVs if they are enabled for WiFi and/or Bluetooth connection. While this avoids using cables, its better to use an HDMI connection because there is no danger of lag or network problems. Its also possible to use an optical cable.

How do I connect my Bluetooth Soundbar to my TV without Bluetooth?

If your TV is not Bluetooth compatible, you can hook up a 3.5mm to Bluetooth transmitter to your audio out jack of your TV. Make sure your TV is set to emit sound through the audio jack rather than the TVs built-in speakers.