Thanks for posting your concern here in the Community. I'd be happy to assists you on how to correct your recording transaction in QuickBooks Online (QBO).
There are two options to record sales transactions in QBO, and it depends on when you receive the payment. For a deferred payment, you can use the Invoice and Receive Payment. However, for immediate payment, you need to use Sales Receipt.
Since this is an installment, you can delete the sales receipt you've created and record an invoice instead. Then, use the Receive Payment function to record the partial payment until the invoice is marked as paid.