From my research, it seems that airlines based in the Philippines don't allow non-Philippine credit cards on their websites. The ticket I will be needing is MNL-PPS (Puerto Princessa)-MNL next year. I can only find 2 airlines with that route, Philippine Airlines and Cebu Pacific.

How do foreign tourists buy tickets? I don't know how full these flights are so I don't want to risk leaving it until we get there.