Opencart stores the price in the base currency, and when displayed on the site in other currencies, it converts it.
Actually, when transferring a product to opencart, we take from it the exchange rate with a code in accordance with our name of the currency and bring it to its base currency at this rate.
On the example of the product
https://forled.com.ua/admin/shop/products/1129/edit/ - at the Opencart rate for USD = 27.1 it will have a price of 51.49 - which is apparently converted to 1.9 USD, respectively, when withdrawing.
Here is an example of an article where this is discussed
https://webocreation.com/blog/currencies-management-in-the-opencart-3/