Hello there, @patdrd.

You can manually enter your exchange rate by selecting Your rate on the Edit currency exchange rate page in QuickBooks Online (QBO).

Here's how:

1. Go to the Gear ⚙ icon, then Currencies.
2. Locate the currency to change.
3. Under the Action column, click Edit currency exchange rate.
4. In the Edit currency exchange rate dialog, choose Your rate.
5. enter the new rate in the field provided.
6. Select Save.

For additional information, you can check this article: Enter an exchange rate. This article also provides more details on how the system calculates the exchange rate.

Please check this article to see steps on how to create a new customer in a sales form and assign a foreign currency: Assign a foreign currency or multicurrency to a customer.

Please let me know if you need anything else with QuickBooks. I'm here to help you out.