Every sport kite should have 2 TOW POINTS.
It is normally where all the smaller bridle lines come together.
There is one on the left and the other on the right.
Many times, the tow point will be a heavier line.
The attachment is done with a Larkshead Knot. You can Google
videos on the knot or watch this: (it's British so it is the best)
David Barnby taught me that.
Here is a Beetle showing the 2 attachment points:
Click on the photo below to go to the larger picture.