Good day, michelleopm.
You can manually enter the rate when recording the payment. From the Receive Payment page, there's a field where you can edit it, below the Customer.
Then, you can check your Exchange Gain or Loss account to see the gain and loss details. Simply go to the Accounting tab and select Chart of Accounts.
I have articles here for more details about multicurrency:
Please post again if you have other concerns. Have a great day!
