Country GeoIP source based policy

Hi, I have been using FortiGate for a week. So I am a bit new. I have a question: I want to know if I can restrict access to my FTP server so that the port forwarding policy only allows connections from IPs from a certain country/countries.

I can't find how to do it, if it is possible to do it.

Thank you very much in advance.

Best regards, Gabriel