Please help me !!!

I have three currencies on my app : EU , GBP , and USD . Every one of them has a different IBAN. Which one is correct? I want to get money from UK to Bulgaria . Is this possible? How can I do that?

All three are correct (you might even have six bank details, three times local and SWIFT).

Which currency does the account in Bulgaria keep? BGN, EUR, or something else?