As of Brexit, DX Express do not support the sending of shipments to Northern Ireland (NI) and the Republic of Ireland (ROI) via the API we use to connect with them. If you wish to ship to ROI or NI will need to do it manually via DX's online Despatch Manager 6 platform. In order to do this you must sign additional commercial agreement with DX, if you are not aware of this agreement I recommend getting in touch with your account manager.
DX do not yet have plans in place to allow Shiptheory, and other platforms, to book consignments to ROI/NI. We will remain in contact with DX and update our integration accordingly if this becomes a possibility in the future.