that article is for desktop only, QBO is different

If you got a refund (check or CC credit)  and did not enter a vendor credit then just deposit the check and use Other Income as the source account for the deposit

If you have a vendor credit already and the refund is for that, then deposit the refund and use accounts payable with the vendor name as the source account for the deposit, then open pay bills, select the "bill" the deposit made and apply the credit, save.