BMW Repair: Adding Refrigerant to A/C, 2004 bmw 325i, windshield wiper

Question
I have a 2004 BMW 325i to which I need to add some R134 coolant to the A/C. The fitting on the can of refrigerant I bought from Auto Zone is too big for the low pressure valve- they will not connect to each other.
Is there a specific can or brand of R134 with the correct fitting or is there an adapter I can buy to put between the can I have and the valve?
I am assuming that the valve I see in the engine compartment is the low side. It is located on the passenger side and is visible just below the windshield wiper.

Thanks for your help.

Answer
no adapter, no different can.

There are two reasons I am aware of that this would not fit:  1, you are on the wrong fitting.  look for the second one.  If it fits the second one, use that.

The second reason is unlikely.  Some cars, like mid '90's Audis', used a special high pressure system that required different equipment.  I am not aware of BMW ever doing this.