First you need to find a homeless man in the slums asking for food, give him food and he will tell you some secrets. After like, maybe five times he will tell you the junk trader sells counterfeit passes to upper new ark
Oh and then go to lin lin and get a massage, i think it might have to be happy ending one though, while holding the pass. Then she will take you to the tat2 place to get a better pass, note it costs more money and it will be used up per visit.
But once one of ur skills is high enough, i forgot which one, you can make ur own at the table if you have a pen (hardware shop), but it might mess up