Add MCUBoot and OTA over BLE with private key

Hi, 

I'm currently trying to add MCUBoot in my project.

The project was built successfully by adding these lines to prj.conf.

CONFIG_BOOTLOADER_MCUBOOT=y
CONFIG_NCS_SAMPLE_MCUMGR_BT_OTA_DFU=y
The memory report clearly indicates that MCUBoot has been successfully flashed onto my board.
I also can see DFU funtion and SMP service work in nrf connect APP.
Here are my questions:
1. How can I use a private key with currently settings?
2. How to update the firmware by using new nRF Connect SDK DFU? More precisely, what files should I prepare for?
Related