If your bank is international then you'll have to use a SWIFT code for your transfer. If it is US-based then please use the wire routing (or ABA) number for your transfer.
Typically SWIFT codes follow the following structure:
First 4 characters - bank code (only letters)
Next 2 characters - ISO 3166-1 alpha-2 country code (only letters)
Next 2 characters - location code (letters and digits) (passive participant will have "1" in the second character)
Last 3 characters - branch code, optional (‘XXX” for primary office) (letters and digits)