Hi there, @AnnaKarp. I'm here to help you record a refund in QuickBooks Online (QBO).
If you got a refund from a business expense, you'll need to create a vendor credit. This depends on how you record your purchases. You can read through this article that details the process: Enter vendor credits and refunds in QuickBooks Online.
If you're not sure how you record your purchases, I suggest consulting an accountant. We can help you find an accountant if you don't have one by clicking this link: Find a ProAdvisor.
You can also visit this article to learn how to refund your customer: Record a customer refund in QuickBooks Online.
I'll be here in the Community space if you have additional questions about recording a refund in QBO. Have a great day!