If you imagine the placement of the horn is on the left side of the bike behind the radiator, The “two prong” harness clip thing is towards the center of the bike farther into that cavity. It feeds up through the frame under the gas tank.
I’m curious, what are you trying to do? Did you get a new horn and you just need to know where to plug it in? Why are you looking for it, and why isn’t it plugged into your horn?