SAMD21 as keyboard

Hey there,
a friend gave me a SAMD21, which he uses as a keyboard with the only letters “A” and “B” and asked me to make a second one. The problem is, that I’m an absolute newbie and can’t find any helpful advice.
I thought I can copy the code from device A to device B and that’s it, but I can’t find any code on device A as it is recognizd as a normal keyboard when connected to my computer.
I installed Mu and Arduito IDE but both don’t show any code, Mu even can’t find the device.
What should I do?

Hello, you can follow the wiki to quickly get started with SAMD21, there is a wealth of routines in the wiki.