How do I change currency on Apple cash?

This is from section 3 - E of the Apple Cash Terms and Condiftions.

>>E. Foreign Transactions.

Once you have registered your Apple Cash Account, you may use your Apple Cash Card for transactions outside the U.S. at eligible merchant locations that accept both Apple Pay and the payment network on which your Apple Cash Card is issued (please see Section 1(F) above entitled “Registering your Apple Cash Account with Bank” for more information on this process). If you conduct a purchase transaction in a currency other than U.S. dollars, the merchant, the payment network for the Apple Cash Card, or other association that processes that transaction may convert any related debit or credit into U.S. dollars in accordance with their then current policies. For example, the conversion rate may be either: (i) selected from a range of rates available in the currency markets (which may be different from the rate the merchant, the payment network for the Apple Cash Card, or other association involved in processing your transaction is actually charged); or (ii) a government-mandated rate. The conversion rate may be different from the rate in effect on the date of your transaction and the date it is posted to your Apple Cash Card.<<

https://www.goldmansachs.com/terms-and-conditions/Apple-Card-Customer-Agreement.pdf%0A

It basically says that Visa will do the conversion, but other entities may add fees as well.

You will also have limits on some purchases. Please review the Apple Support article on transaction limits linked below.

About limits when using Apple Pay in stores – Apple Support (AU)

Short Answer: Yes and yes.

Longer and more complete answer:

Below C&P is excerpted from the complete AppleCash “Terms and Conditions” accessible from within your Wallet.

“… Once you have registered your Apple Cash Account, you may use your Apple Cash Card for transactions outside the U.S. at eligible merchant locations that accept both Apple Pay and the payment network on which your Apple Cash Card is issued (please see Section 1(F) above entitled “Registering your Apple Cash Account with Bank” for more information on this process). If you conduct a purchase transaction in a currency other than U.S. dollars, the merchant, the payment network for the Apple Cash Card, or other association that processes that transaction may convert any related debit or credit into U.S. dollars in accordance with their then current policies. For example, the conversion rate may be either: (i) selected from a range of rates available in the currency markets (which may be different from the rate the merchant, the payment network for the Apple Cash Card, or other association involved in processing your transaction is actually charged); or (ii) a government-mandated rate. The conversion rate may be different from the rate in effect on the date of your transaction and the date it is posted to your Apple Cash Card … “