In principle everybody could find the information because it is already posted here.
So I will give you some hints.

Method 1: Resetting the code with rescue os. Boot with the flasher the rescue os and type.

This will reset your code to the default one "12345".

Method 2: Figure out the typed in code. Boot with the flasher the rescure os and grep the encrypted code from mtd1 and use john the ripper to brute force the code. Wondering what kind of stupid code you chosen in the past and type it in after rebooting the device. Remember the code or change it.

You could use for both methods my rescue live image, so you don't need to install the flasher and don't need to download rescue os because it is on board.