How do i get confirmation letter when my property doesn't have street numbers and street names?

Hi there, ive just joined booking.com and my address doesnt have a street name and number - i live on an island in Moorea, french polynesia. How am i supposed to receive the "confimation letter" - i do have a POBOX in town - Should I put that as my location? Next how to i change my location to that? Help please.