The PDF attached invoice have an different order number than the e-mail invoice

Hi,

There are two numbers:
- the order number (created when the order is created
- the invoice number (created when the invoice is created, generally when the order status is changed to "confirmed" after the payment)
In the invoice, you get the "invoice number".
And in the order notification email, you get the "order number".
Now if you want the order number and invoice number to always be the same, you can enter the tag {order_number} in the "invoice number format" setting of the HikaShop configuration.