Currencies are selected per payment processing account, as a part of the initial setup process. To make sure your payments are successful, assign each listing to a payment processor which supports the listing's currency. For example, if the account in the payment processor is set for USD, the listing's currency in Guesty should also be USD. You can always change the listing's currency to match the configuration of its associated payment provider.
GuestyPay, Merchant Warrior and Hyp do not handle currency conversion. If the currency configuration of the listing and its associated payment provider do not match, the payment will fail.