Which android debug hash key to add in Facebook Application ?

I and my friend is working on a project where we need to share post on Facebook. We both have imported Facebook sdk, now I and he has different android debug hash key in Facebook setting menu in unity. So, I am confused that which of us key goes to Key Hashes to Facebook application's android setting and when we put our game to playstore , do we need to change key hashes of android setting in Facebook application ? Do let me know if there is proper documentation on it and please help me come out of this issue. If I put my hash key it's working fine in my build, but not able to see the title and description in share dialog of my friend's build.