External third party transports can be uploaded into Transport Expresso via the TE Windows GUI and also the SAP GUI.
This can be done by any user, and is not a Administrator function.
There is no pre-requisite activity required in terms of creating RFCs or TE Targets to upload external transports into Transport Expresso
Adding External Transports in the TE Windows GUI
External Transports are added in the Windows GUI via the External Transport Request option on the [New Transport Form] screen.
From this screen, the cofile and data file for the external transport is uploaded to either the TE Domain Controller or a specific local development system.
When you first add an external transport, an entry is created to link the SAP transport prefix (SID) to the Domain Controller or the local Development system that you selected. From that point onwards, the system that you chose will always be where external transports of that SID are uploaded. (this information is stored in /BTI/TE_TARG_EXT table in the Domain Controller)
A TE Transport Form can then be populated for the transport, and moved through the approvals workflow in the usual manner.
Adding External Transports in the SAP GUI
For any TE users that prefer to upload external transports via the SAP GUI instead of the TE WIndows GUI, this can be done using program /BTI/TE_RUPLOAD_TR_REQUEST in the TE Domain Controller.