This is a security measure implemented by Yahoo. Normally, the system considers this is an attempt to hack your account, because it records the places you use on your home country and allows you to access it, but if suddenly the usual access location was changed, then the security has been triggered. If you don't enter that access, the Yahoo account won't be able or available for purchasing. You will need to ask someone in your home country to log-in with your account, and then add an additional email. This way you will get the code to other email.