Welcome and thanks for reaching out to the Community!
Creating an invoice with a different currency is pretty easy in QuickBooks Online (QBO). All you need to do is to turn on the Multi-currency feature first. This can be done by going to the Accounts and Settings.
Go to the Gear icon. Then, choose Account and Settings.
Select the Advanced tab.
Go to the Currency section.
Turn on the Multicurrency. Note: Once multicurrency is turned on, the home currency is set and cannot be changed in QuickBooks Online. Read and check the box to acknowledge that you understand you can't undo Multicurrency.