is it possible to code a keypad or combination for a lockable object if so how would i do that

Someone else asked about combination locks fairly recently. [link]. Somewhere in that thread I offered some thoughts on how to make the scripts work with a lockable container rather than a door, though it's quite a lot of work.

Depending on the type of lock you require, it might be easier to use get input and check if the value entered is the correct combination.