Okay, incandescent bulbs like those draw a lot of current. That means a relay will be required, which isolates the bulbs' heavy current draw from most of the circuit like the on-off switch.
If you power the relay from the high beam lead, you can instantly shut the high beams and KC lights off together with the high beam switch which works well when you suddenly encounter oncoming traffic. Having to contend with two different light switches while blinding oncoming traffic is not good.
Like this schematic. If you move the green wire so it connects to the high beam instead of the low beam it'll work like that. So the KC lights only work when the high beams are on.