How do I set up a product in USD?

Hello gsp1,

Welcome to Community!  Using multicurrency in QuickBooks Online is beneficial in providing various currencies in one platform.  It enables you to pay and get paid in foreign currencies for customers and suppliers that don't use your home currency.  Although there currently isn't a way to add products and services with foreign currencies, you can add the suppliers for such products.

Here's how;

1. Open Expenses, then Suppliers, from the left menu

2. Select New 

3. Complete the fields in the Supplier Information window

4. Hit Save.

Click here to see how to add multiple suppliers in one batch.

If you have any other questions, feel free to reach back out.  We would be glad to help!