If your bank is international, you'll have to use a SWIFT code for your transfer. If it is U.S.-based, then please use the wire routing (or ABA) number for your transfer.
Typically SWIFT codes follow the following structure:
First four characters - bank code (only letters)
Next two characters - ISO 3166-1 alpha-2 country code (only letters)
Next two characters - location code (letters and digits) (passive participant will have "1" in the second character)
Last three characters - branch code, optional (‘XXX” for primary office) (letters and digits)