Good day, @LilyLizalde.

I'm here to lay insights about linking sales orders to invoices in QuickBooks Desktop.

You can delete the invoice and reconnect the sales order. Then, modify the invoice to avoid charging your customer twice. When you collect payment for each item on the invoice, the item is marked as closed on the sales order. You can precisely track your income by deleting the invoice associated with the sales order.

However, we're unable to link sales orders with amount to an invoice. You'll need to copy the line items, then subtract the total from the invoice. As a result, each item on the event will be zero.

Moreover, if you need to access your sales report or customize reports, have this article for more details: How to run and customize reports in QuickBooks Desktop.

Please don't hesitate to comment below if you have other questions. I'd be happy to assist you further. Take care!