I found the high side nipple of ac on the condesor but I can't find the low side fill nipple to charge the AC on a 96 A4 2.8 V6 Quattro, where is it? any help would be appreciated

 

I am not an expert under any circumstances but as far as I understand in 96 they put 2 kinds of compresors in the AC system, I'm attaching some diagrams of them maybe they will be useful. The new nippondenso compresor was put in all the 6 cylinders engines. It's the first one on the list.