Register/record the conversion/exchange rate in the DB at the time of adding a transaction (additionally, a field can also be made available to manually enter the exchange rate; the default would be auto, which would use the already-fetched exchange rate at the time of adding the transaction) other than the base currency. This would ensure accurate tracking of financial transactions, especially for users dealing with multiple currencies. By storing the exchange rate at the time of the transaction, users can maintain more accurate records, calculate the correct amounts in the base currency, and avoid issues due to fluctuations in exchange rates over time.