It was not. I vaguely recall that during my onboarding (which was long before I needed to use the code) I was asked to pick a code and I needed several attempts.

Funny that If it was possible, codes like 1234 would still be almost guaranteed to be valid, but because the code needed to be unique, there were far more valid codes, which made the guess even easier.

Plus when trying to pick my own code during onboarding I could note all the failed attempts as also valid codes.

So much fun! :D