How do I update the currency exchange rate?

Excuse me, could you please clarify for me how one would typically go about updating the currency exchange rate? Is there a specific process or platform that's commonly used for this purpose? Are there any specific steps that I should follow to ensure that the exchange rate is accurately reflected in my transactions or systems? Additionally, how often should I be updating the exchange rate to keep it current and accurate? I'd appreciate any guidance you can offer on this matter.