Some features are unavailable if the feature is turned on, Psvirtualbookkeeping. Let me share them with you.
 

The process is irreversible once you turn on the Multicurrency feature. Also, these are the following features that are unavailable when it's set up:

• You can download current exchange rates only. If you haven’t downloaded it for some time, you'll have to enter the historical exchange rates manually.
• You can set up static foreign prices using the per-item price levels. However, you're unable to do the same to create static foreign unit costs.
• You can't enable the online payment of invoices in multiple currencies.
• You're unable to auto-memorize the transactions in foreign currency.

I'll share an article that will guide you about the feature: Multi-currency in QuickBooks Online.

Reach out to us again if you have more questions. We'll address them as soon as we can. Keep safe!