I have booked my flight from London to Iceland. The flight ticket says London Heathrow Apt - Reykjavik Keflavik Internationl Apt. I checked on Google Maps; it shows Reykjavik Domestic, Reykjavik International, and Keflavik International - all three as different airports (although the first two are very close or probably the same, whereas Keflavik one is far from the other two; about 41 mins drive according to Google Maps).
Now I need to hire a car from the airport. Which airport should I request car hire from?