I live in Mendoza and I need a multi-entry visa for 12 months.

I am going to be in Mendoza for a couple of weeks, I am an argentinian citizen that lives outside of the country and I need to get a multi-entry visa for 12 months for China. Do I need to travel to Buenos Aires and I apply in person for my visa or can I send all the documents in the mail? If I need to go there in person, do I need to set up an appointment?
Thanks!