Hello there, @KC
Allow me to share some information about your concern about payment on invoice not appearing as revenue on P&L in QuickBooks Desktop.
To get started, please check the accounting method you are using. If you are using the accrual method, the report will only display unpaid invoices. However, if you are using the cash method, the report will show paid invoices.
If the report does not show the correct information, you may need to verify that you have selected the correct reporting date. Also, double-check the dates of the invoices and payments. Furthermore, make sure that the items listed on the invoices are linked to an income account that accurately reflects your sales.
You may refer to this article to learn how to customise the data, add or delete columns, add or remove information on the header/footer, and even personalise the font and style of the report: Customise reports in QuickBooks Desktop
Let me know if you need further assistance with your payment on invoices or your Profit and Loss Report in QuickBooks Desktop. I'll be here to lend you a hand. Take care!