You will find that on almost all (if not all) of the international destinations that you cannot do OLCI, this is because they need to check your passport. Airlines don't want to be fined so if they were to let you check in without showing them your passport and visa (if required) they would be hit with a huge fine and you would be coming home on the same plane you arrived on. They will require you to go to the GA working the flight as well and look at your passport/visa and stamp "DOCS OK" on your Boarding Pass.