You currently support Parcelforce services including Euro Priority and Global Priority, but you do not have Global Express unfortunately. This is Parcelforce’s fast service, which offers 1-2 day delivery to most locations worldwide. An increasing number of customers are now asking for this, so we need to be able to do these orders from within ShipStation.
Given that you already support other Parcelforce shipping methods I don’t imagine it would a huge effort to add Global Express.