You must enable multi-currency in QuickBooks

How to enable multi-currency in QuickBooks Online to resolve currency errors.

Turning On The Multi-currency Feature

You can change your home currency from the same place that you enable the multi-currency feature. 

Follow these steps:

1. Click Gear →   Account and Settings.

   QuickBooks Online displays the Account and Settings dialog box.

2. Click Advanced.
3. Scroll down to the Currency section.
4. Set your home currency by clicking the Home Currency list box.

   Choose the currency of your country. If you’re not in the United States, don’t set the United States as your home currency.

5. Select Multicurrency.

   QuickBooks Online warns you that, once you turn on the Multicurrency feature:

   • You can’t turn it off, and
   • You can’t change your home currency.
6. Select I Understand I Can’t Undo Multicurrency.
7. Click Save.
8. Click Done.