does Apple Pay work internationally?

No, you can only send to and receive money from people in the U.S. However, the virtual debit card associated with the service (the apple pay cash card) may still be used to make purchases outside the U.S. anywhere Discover cards are accepted and contactless payment is supported, and a 3% fee will be incurred by such purchases (source: the apple pay cash card terms and conditions, by Green Dot Bank).

Hi

No, you cannot.

For Apple Pay Cash, both users must be US residents (and aged 18 or over):

Send, receive, and request money with Apple Pay - Apple Support