Can Am McAllister, OK, where I bought my 2020 Defender, said to pry the switch panel off that is right in the center of the dash and also has the key ignition switch on it, and I would see the buss bar. The buss bar doesn't look like the one under the hood. You will see two lonesome looking screw post sticking out from the box that has the extra auxiliary wiring zip tied to it.. They do NOT look like what I would think an electrical connection would look like but it is the treaded silver color post with no nut on it, is the negative and the other silver treaded post is the KEY ON Positive post. It has the red tape on it. Using the Key On positive post, you will not drain your battery. In the picture of the "box" that has the posts sticking out can be seen in the earlier posted picture above. The silver negative post is seen on the upper right side and the one with the red tape is sorta hidden in the picture, but also seen on the right.
The positive post under the hood is straight to be battery, no Key On circuit here.