It's connected via USB. You can use either one of the two USB ports in the car.
Little bit of extra information in case you're interested. The LED strip is a 'BlinkStick Flex'. The android app on the HU communicates with the device via this USB connection. You can code it change colour of all...
I ended up getting bored so I bought some controller LED strips and built an android app that runs on the Civic's head unit in order to customise it. Lights up the driver-side footwell. Still early days but it's something!