Customer order number

Hi all, I recently upgraded my desktop version but now the Customer order number field is missing in Sales Invoice, is there any way I can include this by customising?
Thank you for any help.
Cheers
Pete

If you are using Sales Orders tab, you can link sales invoice to sales orders which will allow you to track orders. See: https://www.manager.io/guides?sales-orders

However if you are not using sales orders tab and just want to record order number somewhere on the invoice. Then create custom field on sales invoice level. See: https://www.manager.io/guides?custom-fields

Thank you lubos for your help, I don’t use sale orders so I will follow your suggestion.
Cheers
Pete