I have a prestashop store with amazon marketplace module. It is configured with my API data, but i can't export my catalog. Module say me that no exist products to export to amazon... Many products haven't ean code, but I agreed with Amazon that i'm exempted of give this field and i can add products without ean code, but module seems that not permit it.
My brand is approved with amazon for EAN exemption, you have to modify module to permits export without EAN code.