How exactly does the apple card work internationally?

I travel a lot and would like to buy a new iPhone on a payment plan. I won't be able to buy it in my home country. As long as I load money onto the card, can I begin this payment plan anywhere?

I may buy it in Indonesia, Singapore or Australia. I am South African and am constantly moving from country to country for my work. I would link my South African Bank account to the card. What hoops would I need to jump through to get it to work that I can buy an iphone 11 pro on a payment plan anywhere in the world using apple card. What are the pre-requirements for this to be possible?