Is it possible to convert the Purchase Invoice in to Sales Invoice?
Yes. You can convert the created purchase invoice in to sales invoice.
Click on the Purchase module and select the option Purchase Invoices.
Click on the menu, Add new purchase invoice on the top right side of the page and need to enter the details to enter the details to create a new invoice.
Click on the save option to create new purchase invoice and it opens to Purchase view page.
Purchase view consist of various menus and more options.
Click on the more options menu on the right side of the invoice view and select the option Convert to Sale.
It opens to Sales invoice form and click on the Save option to create sales invoice.