To Restore the Cancelled Sales Invoice, Please Follow the Below Mentioned Steps.
Step-1: Kindly go to Sales >> Click on Invoices.
Step-2: Click on Cancelled and search for the customer/Invoices whom you want to Restore >> Click on Restore.
Step-3: After clicking on Restore You will get a notification, Please click on proceed.
Step-4: Checked the details in the invoice and click on save to Restore the Invoice.