Duplicate an order completely or copy only the products in the order to generate another for another client is a very simple process.

Copying the order for the same customer

Database > Sales / Invoices > All orders > Select the order > Tap on the double sheet icon

All the products will be copied to a basket on the same customer keeping the same prices and discounts that were given in the original order.

Once you have the basket, it can be modified by adding or removing products, changing prices, dates, etc.

Copying the order for another customer

The process is the same even when the basket becomes an order specifying that it must not be delivered. Only unshipped orders will show the client in yellow, meaning that you can change it.