Yeah, I'm dumb, but I cannot figure out what you mean to do.
I pull out the cable and I have a long cable.
That does not seem to lock anything.
I would suspect that the cable comes out, loops through the bikes, and then reattaches to the bike rack in such a way that it makes a loop, and the end is locked...
So, you covered step 1, but I cannot figure out where to reattach it, how to make sure it's locked, etc.