Tow bar, heated steering wheel and harnesses

Hi there, today i got a reply from my supplier about the tow bar (I almost forgot it as I did almost 6 months ago!). He proposed me the Skoda Kit, including everything to fit on my car, that means control unit (coded), bolts, switch and harness.

Looking for what these parts are, I read there’s harness for car WITH heated steering wheel and car WITHOUT: can someone explain me which is the connection between the heated steering wheel and and tow bar?

As You also know, I’m trying to retrofit the heated but I’d like to know what it may happen if I install the tow bar without the proper harness for the steering wheel.