BuddyPress.org

Hi guys.. i’m not new to WordPress but on Buddypress. I’m trying to build a community site and i need to have a listbox on the profile page that use a json file from url to read the options. I’m trying to understand the buddypress but i didn’t yet.
The API that i’m willing to use is http://fipeapi.appspot.com/ and the code that i’m using initially is this one. Stackoverflow
Do i need to make an Xprofile plugin? I’m lost xD
I don’t have much idea on how to make this… i also need to save the selected option for each profile.

Any answer will help! I need some orientation, thanks in advance!