If you want to edit an invoice that has already been issued with a receipt, you must cancel the receipt and payment record for the invoice before you can make any changes to the invoice. The steps are as follows:

Step 1: Select the 'Revenue' menu, then choose 'Delivery Note/Invoice/Record AR', and select 'Paid'.

Step 2: Select the invoice that you want to edit, then click on the 'View Receipt' button in the Action row.

Step 3: Cancel the receipt by clicking on the dropdown menu and selecting "Void" option.

Step 4: After clicking on "Void," a pop-up will appear asking for confirmation to cancel the document. You can select "Confirm" to proceed with the cancellation.

Step 5: Go to the invoice >> select the payment tab >> click on the three-dot icon and choose "Void" to cancel the payment record.

Step 6: Once the payment has been successfully canceled, a pop-up will appear asking for confirmation to cancel the payment. You can select "Confirm" to proceed with the cancellation.

Step 7: Then, you can edit the invoice by selecting the "document" tab, clicking on the dropdown menu option and selecting "Edit" from the options provided.

Step 8: Once you have successfully edited the information in the invoice, click on the "Save" button.