Issues flashing IO firmware on Pixhawk 6X baseboard

Hello Dev Team/ everyone, I hope you all are doing great.

We have designed a baseboard using the 6X schematic that was provided in the PX4 Holybro.

We have fabricated the baseboard, and when we connect the baseboard alone, only 2 green lights are flashing without blinking.
It is not detected from the device manager and so from Qgroundcontrol since there are no firmwares that were loaded on the STM controller.

We have followed these steps.
Bootloader Update | PX4 User Guide (v1.14),

wherein we tried to flash both the 6X and the baseboard that we fabricated by creating the bootloader file using the above steps.
We got the following messages:


not showing done…

Additionally, we got the timeout error in the “Qdsupport” response along with the “VMustReplyEmpty” error in gdb 9.1 version.
This method was also tried Remote replied unexpectedly to ‘vMustReplyEmpty’ · Issue #9 · pulp-platform/debug_bridge · GitHub
and we downgraded to >7.7, we got a Cmake errors.

How can we flash the baseboard alone using the STM Debugger PX4-Autopilot/src/modules/px4iofirmware at main · PX4/PX4-Autopilot · GitHub
If we try with the bootloader, we got the above-mentioned error when we tried connecting via FMU debugger whilst connecting with the stock controller on the fabricated board.

Ubuntu OS version 20.04.