At the top right corner of the screen click on the tool icon and choose the Property Settings / Financial Settings / Currencies & Accounts:
In Property Currencies choose the Property Default Currency:
In order to add new currency click on the button Add Currency and choose it from the list:
A) You can configure the exchange rate manually in the RATE column. In this case, the boxes in the AUTOMATIC column must be empty.
B) If you prefer that the change is automatic, check the boxes in the AUTOMATIC column.
The automatic exchange rate used in FrontDesk Master is updated by openexchangerates.org
C) You can also use the automatic gearbox adjusted by you. In this case, check the boxes in the AUTOMATIC column and configure the setting in the ADJUSTMENT VALUE column.
Remember to save all changes.