Glad to see you in the Community again, @deleted filed tax return.
Currently, you can import transactions such as invoices and bills in QuickBooks. However, this isn't available for credit notes.
You can check this article for more information about the list of data you can import: Common questions about importing data to QuickBooks Online.
In the meantime, you can manually create the list of your credit notes. Here's how:
Additionally, you can refer to the following articles for the steps in handling credits and refunds.
Handle a customer credit or overpayment in QuickBooks Online
How do I handle supplier credits and refunds?
Let me know if you have follow-up questions. I'm here to help however I can. Have a good one.
Utilize TP Importer
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