When auto picking an order it can be done based on Item pack size. One carton can be created for one pack.

For example: If an item AA has item pack size as 6 and if the order quantity is 6, the item will be packed into 1 carton. 

This can be set under Warehouse Settings;

Item pack size can be defined in item details.

With above settings if you auto pick an order it will create cartons based on the pack size.

Please contact The Order Exchange Support (support@theorderexchange.com.au) if you have more issues.