Use the nrfutil nrf5sdk-tools dfu (or dfu) command to transfer a Device Firmware Update (DFU) package to a device compatible with the nRF5 SDK. The package you transfer can for example be the one you have generated using the nrf5sdk-tools pkg command.
Make sure that the transport you select matches the DFU bootloader that is installed on the DFU target device.
Tip
For more information about the DFU process in the nRF5 SDK, see the nRF5 SDK Device Firmware Update process page.