If your system has different currency than your profile in the booking portal (For example, in the system your default currency is Peso, but in Booking.com your profile is set up in USD.),

it is critical to make sure that in MANAGE / ONLINE PORTALS in the specific portal you selected currency of your portal's profile:

Now, you can set up the price in the selected currency in your room pricing:

If you leave prices "0" for the secondary currency, then HostelSystem will calculate the price automatically using the exchange rate from ADMIN / Accounts & Currencies: