FBI background check (Buenos Aires)

Hey everyone. American here born and raised 28 years in NJ. Just have a quick question maybe someone can point me in the right direction.

I'm trying to get my paperwork together for a DNI with temporary residency. I have a lawyer that is helping me with the process and she is telling me that I am in need of a FBI background check from the USA. She told me to go to the US embassy and that they would help me with that, but I couldn't find anything on their website.

From what I understand I have to send in a request form with my fingerprints through the mail. Was just wondering if maybe there is an agency in Buenos Aires that does the process or if I have to do it all myself, where would I be able to go to get my fingerprints properly documented on the paperwork I have to mail out?