Customs and importing (EAD) in to the UK

I have a customs agent and shipped my first batch today from Latvia factory to Amazon UK via FedEx road shipment. Provided all the documentation to the agent and FedEx. However, now they are asking me for the EAD export accompanying document’s (I have paid for the importing and delivery costs directly to my supplier). Now my question is, who will need to provide the EAD? Myself, FedEx or my supplier/factory to the agent? My Ltd. is listed on all documents/invoices.