Use the nrfutil device program command to program firmware onto connected devices.
The command is the same regardless of whether the programming is over SEGGER J-Link, MCUboot serial recovery, nRF9160 modem upgrade, or other. nRF Util automatically selects the programming method based on the device traits of the connected device and the firmware file format.
nRF Util supports programming of all Nordic Semiconductor Development Kits (DKs), prototyping platforms, and dongles.