Where is the low pressure port for recharging air conditioning on a 2001 Volkswagen Jetta 1.8T?

The low-pressure port for recharging the air conditioning system on a 2001 Volkswagen Jetta 1.8T is located on the passenger side of the engine compartment, near the firewall. It is a metal fitting that has a plastic cap with a blue or green color (depending on model year). The cap can be removed by hand or with a screwdriver, and the port will be visible underneath.