Air Cond on 1996 Chevrolet Monte Carlo

I want to recharge the AC but can't seem to find the low side fitting to replace the freeon

The A/C fittings may be under the air cleaner housing. Your A/C system should use the new 134a refrigerant. Please make sure you have the proper equipment to service the type of A/C system.
Where is the Air Cleaner Housing?
I have A 2001 Monte Carlo SS
omg look under the hood and it will be a big black box on most cases.