Hi. How could I apply for my registration to be born in the consulate here in Miami? Since I reside here and obtained my citizenship in Cuba, I would greatly appreciate your response. Thank you

If you are a Spanish citizen you can do any procedure through the consulate of said citizenship

You must fill out a form with your data which appears on the website of the Spanish consulate and send it to the consulate here in Miami, which sends it to Havana and then Havana sends you the certification through the consulate here in Miami so that you can register for consular registration and get your first passport.