In the case of Argentina, which is a case in of its self, we convert the P&L and Balance Sheet to USD. This helps with normalize the jumps one sees YoY. One should use the exchange rate from the BCRA (Central Bank). Because Argentina has had a lot of differences in its exchange rate, companies exporting good and services may see a jump in previous years. In that case, you should adjust accordingly and normalize earnings and EBITDA. I you want to get picky, you should also take into account the inflation in USD for Argentina, this information could be used for projections, but you can use the inflation rate of USA to facilitate calculations. The interesting aspect of doing projections in Argentina, is that it’s difficult to do them because of constant political and regulatory changes.
Side note, it’s better practice to use an average exchange rate, monthly or yearly depending on the information you have.