Dear Amanda, as William commented above, you should look for the American consulate closest to your residence. The Brazilian consulate in the United States only registers for Brazilian citizenship for minors who were born on American soil.
I've read everything it says on the consulate's website and I didn't understand it at all. First it says that both parents must be present, but that is not possible. Then he says that if the father who is transmitting citizenship cannot be present, he has to fill out another form, but they must be signed in front of a consular agent. Where will he sign it?
You have to go to the American embassy closest to you. Before that, there is an application that you need to fill out on the American Embassy website. There is no need for any organ in Brazil to help you. All American organ for you to get your child's documents
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