First of all, the EAN must be stored for each SKU, because this information cannot be reliably taken from the Amazon report.
1) Start in the menu SKU Database and activate the column "Custom Product ID".
2) Add the EAN in the SKU.
You can also upload this information via Excel upload for all SKUs.
Finally you can use the placeholder *|CUSTOM_PRODUCT_ID|* to display the EAN on the shipping labels and in the e-mail table.