UPDATE, September 23, 2020: Nikon has released Webcam Utility for macOS in addition to the previously available Windows version.
This morning, Nikon released a beta version of its Webcam Utility software for a variety of Nikon DSLR and Z series mirrorless cameras, including the upcoming Z 5.
The software lets Nikon users use their cameras as webcams, connected to their computers via USB. Webcam Utility is currently available for Windows 10 users.
Supported mirrorless cameras include the Z 7, Z 6, Z 5 and Z 50. The D6, D850, D780, D500, D7500 and D5600 DSLRs are also supported. Nikon also recommends that you adjust camera settings before connecting the camera to the computer.