I proceeded according to the manual.
* For testing purposes, proceed with the SKR mini e3 v3.0 motherboard.
* I can configure it. because, I have already experienced configuration through mainsail. (Voron 3D printer)
1. As in the manual, in [Printer configuration wizard], select klipper for firmware and install it.
2. Go back to klipper configuration and select build micro-controller.
3. After setting the klipper firmware configuration according to the value of the main board, press Q to exit.
Mini e3 V3.0: STM32G0B1 + 8 MHz crystal + 8Kib bootloader
(E3 motherboard sometimes GPIO as !PA14. However, it is not possible to connect with repetier regardless of whether or not.)
4. Select download micro-controller file
5. Rename the downloaded file to firmware.bin and save it to the SD card.
6. Printer power off
7. Insert the SD card into the main board.
8. Printer power on
9. Unable to connect.