A session management function (SMF) receives a request message from a network exposure function (NEF). The request message is for a delivery of a trigger to a wireless device. The request message includes a trigger payload and a trigger indication. The trigger payload includes information for an application on the wireless device. The trigger indication identifies that the request message carries the trigger payload. The SMF sends, via an access and mobility management function (AMF), a non-access stratum (NAS) message to the wireless device. The NAS message includes the trigger indication and the trigger payload. The SMF receives, from the wireless device via the AMF and based on the trigger payload, a request to establish a packet data unit session for the application.