If you would like to change the number of copies printed of a document, it can be done in any of the following locations
Admin / Manage Invoice Layout (Check for the relevant layout)
If it is a POS layout check these as well. Check below for instructions to check in Command Mode
Control Panel / Devices and Printers
Help / Report / Label Editor
If there are a large number of POS users:
Tab to Doccopies and check and change if necessary.
See here to Modify on the Report