Nikon D780 DSLR Camera (Body Only) - Manual (Page 499)

453 Network Connections
The WT-7
When attached to the camera, the optional WT-7 wireless
transmitter can be used to connect to computers, ftp servers, or
other devices over Ethernet or wireless networks.
D Before Using the WT-7
Before using the WT-7, confirm that the firmware for the camera and WT-7
have been updated to the latest versions. For more information, visit the
Nikon website for your region.
Connecting to Networks Using the WT-7