I am using this code, and it works very well.
Now, due to an expansion and the use of a multi-currency system, it is necessary for the value currently displayed in Euros to change. When an order is placed from the USA, the value from the code should be converted to USD, or when the website language is switched to Czech, it should be converted to Czech koruna at a predefined exchange rate.

How can this be achieved? Currently, the value is displayed without being converted based on the exchange rate of the selected currency.
If the value is set to 100 EUR, when switched to USD, it still shows 100 USD, or when switched to Czech, it shows 100 Czech koruna.