Hi. Thanks for the reply. the thing is that i already have Automatic currency rates configuration ticked, and all the currencies are already set. but i still have the same problem, the rate not conversing

In order to enter amounts in a different currency, you need to first set the exchange rate for that currency in the system. 

You can do this by navigating to the "Accounting/ Configurations/ Accounting/ Currencies" menu and creating a new currency or editing an existing one. 

Once the exchange rate has been set, you can then enter amounts in that currency in the journal entry and the system will automatically convert them to the company's default currency using the exchange rate you provided.

In order to update currencies on a automated basis:

Navigate to Accounting / Configurations / Settings and search for Automatic Currency Rates:

Configure your setup and scheduled next run. This will help to update exchange rates based on your run cycle.