Hello Philippe,

you can create an order number composed by custom text with this code in the HEAD section of the whole website (step 1 | Advanced Settings | Head section)

This code as example creates an order number composed by 5 numbers:

<script type="text/javascript">
x5engine.boot.push(function () {
    x5engine.cart.manager.settings({
        "order_no_format": "[0-9][0-9][0-9][0-9][0-9]"
    });
}, false, "last");
</script>

The Program is not generating invoices but order emails. The invoice needs to be made by you once you verified the payment.

Many thanks!