In the online accounting program mKsiegowa.pl you can to issue and print invoices for previously issued receipts.
Issue an invoice
In the module Sales, use the option Invoice for receipt.
Find the receipt on the screen and click the icon 
on the right to issue an invoice.
Note: if there is no icon in the line of a given receipt, it means that the invoice for this receipt has already been issued.
Continue issuing an invoice for a receipt on the next screen.
Batch invoice
To issue a batch invoice for several receipts, select the receipts and click Batch.
Entry in the VAT inquiry
The invoices for the receipt are not recorded in the VAT inquiry. This is because normal procedure is to post a daily report with an accounting document. This could result in a double entry of the sale in the VAT inquiry.