Hi, the Apple Card is a MasterCard and is accepted worldwide at any merchant that accepts MasterCard. It is not dependent upon the use of Apple Pay. Another advantage of Apple Card is that it has no Foreign Fees for use outside the US. Many credit cards charge 3% or more for using it overseas. This is better than that 2% you might earn for Apple Pay. Your Apple Card will still earn 1% in Daily Cash Back for all transactions.
While Goldman Sachs Bank (Apple Card issuer and service) does not require advance notification of foreign travel, in my experience, it is always advisable to notify a bank/credit card company of travels outside your normal home region.
Safe Travels and I hope you enjoy your trip.