Last night I used the method explained in that kodi forum thread, which @dentaku65 refers to.
It worked for me, but it's not simple.
I would assume that it's the best option, since someone else won't be using the same API key.
That thread has a link to a modified version of the addon, that evidently will occasionally require logging in and out. (to acquire a new API key from a pool)
For that reason, I figured that the custom API key method, while more complicated, is a better long term option.