How to get the serial number from RB951Ui-2HnD

Hello,
I am trying to get the serial number from the board of a RB951Ui-2HnD, and I can't find a way to do it. I saw that the dmidecode method doesn't work on mips architecture. I tried searching in /dev/mtdblock ( https://forum.mikrotik.com/viewtopic.php?f=3&t=62444&p=703808#p703808 ) but without success. Is there a way to get the serial number? Beacuse in RouterOS the serial number is displayed in the configuration interface which means that it is written somewhere in the device. Thank you.

Regards,
Vlad