Look in the Payment Issues forum for posts by a guy named Monday something-or-other. He has a post that gives detailed instructions.
You could also just ask the Contact Us folks at the bottom right of this screen how you would enter the Payoneer info. There are writers from South Sudan, South Africa and other places that I know publish with KDP, and they use Payoneer. Be polite and give them details. They probably have a standard Payoneer answer prepared by now anyway.
Note that there is at least one fee associated with Payoneer, so do your research before you sign on.
I have seen posts where authors from South Sudan, South Africa and some Asian countries swear by Payoneer, but I haven't personally used the service so I can't comment on it.