Please check document flow tab or reference tab at header level of your shipment. If you don't find it. then it means the shipment was created manually in GTS.
As Dhilipan says, please check the Reference tab of your Customs Shipment. That shows all related documents (for Import; the Inbound Deliveries having the same Movement Reference Number as the Transit. for Export; the causing Billing Document and related Outbound Deliveries).
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.