If your Gift Exchange organizer has enabled the Participant International Shipping Option, you will be able to indicate whether or not you are willing to ship internationally when you RSVP to the Gift Exchange.
If you are willing to ship internationally, check the box on the RSVP page.
If you forget to check the box while you are RSVPing or wish to change your reply, you'll need to click "Change Reply" on the left side of your Gift Exchange page. The RSVP form will appear and allow you to change your reply indicating whether or not you are willing to ship internationally.
You may still draw someone within your own country if you check the Willing to Ship Internationally box.