Your property can be set up with as many exchange rates as you want, but when you set up your property's general settings you need to choose default currency.
Go to Main menu > Settings > Property.
Click Exchange rates.
In the Currency field, select the currency you want to add.
You'll be redirected to the list of your active exchange rates.
Under the To column, enter the value of the currency you just added against your default currency.
For example, if your default currency is 'ABC', and you're adding an exchange rate for 'XYZ', you could enter "2" under the To ABC column (this would mean that 1 ABC can purchase 2 XYZ).
Select the checkbox in the Is accepted column to enable the currency.
Click the arrow buttons between the To and From columns to reverse the exchange rate (for example, if you accidentally entered the exchange rate from your default currency against the new currency you're adding).
Managing exchange rates
After you set up your exchange rates, you should keep your exchange rates up-to-date to prevent discrepancies. You should either:
Manually update your exchange rates at least once per month.
Connect to the exchange rate provider integration, which will automatically update your exchange rates for you.
Between the time a reservation is created and the time it's settled, exchange rates may change. If the rate group of the reservation has automatic settlement enabled, then the exchange rate at creation will be locked in. If not, an adjustment will be posted to the guest bill.