Mysterious code to a safe
I have a key safe attached to the wall of our house that was from a previous owner. I have no idea of the combination. It is made by Supra. I am hoping to crack the code- I am going by the assumption that it’s a 4 digit code but I am not sure if the safe can accept 2 digits the same- for example, 2024, as when I do that when you press the number 2 for the 2nd time it does not make a click. If that is the case I need to enter every number between 1023 and 9876 (I think!) while missing out double digits numbers.
If anyone has one of these key safes could they please advise on how the number system works.
Thanks in advance.