Hi there, warren-alvern.
Welcome to the Online Community. Let’s use the Discount feature to capture the settlement transaction and then add it on the invoice.
The first thing to do is to turn on the option in your account. Here’s how:
This will add the discount field to the sales transactions. To apply for the settlement, choose which type to use (Discount percentage or Discount value).
For an overview of the feature and detailed instructions to set it in QBO, check out this article: Add a discount to an invoice or sales receipt.
Reach out to me whenever you have additional questions or concerns. I’ll be right here to assist further. Have a great rest of the day.