I'm here to ensure that you can create a credit memo to refund a customer in QuickBooks Online (QBO), @AlexisR.

You can create a credit memo and then write a check for the refund if you want to reimburse the customer for the returned items.

Here's how:

1. Sign in to your QuickBooks Online account.
2. Click on + New then select Credit memo.
3. In the Customer field, choose the specific customer.
4. From there, fill in the Credit Memo Date, Amount Tax, and Product/Service.
5. Once done select Save and close.

You can then issue a refund using a check. However, if the customer wants to keep it as credit for their next invoice, you can use the credit memo to record the transaction.

For more information, you can check out this article: Record a customer refund in QuickBooks Online.

For future reference, you can visit this article that teaches you how and when to give a credit memo or delayed credit to customers: Create and apply credit memos or delayed credits in QuickBooks Online.

Don't hesitate to reach out if you need further assistance with managing your invoices in QBO. I'll always lend a hand.