KeyStore - Play Store problem

Hi, i have a problem. I finished my game, then I looked for how could I publish it on the Play Store. The build was okay, but I should make a subscription key (KeyStore) for the Play Store to accept my game, then I got it. But, in the next day, i didn’t know how to login with that key, so i deleted her and create a new. I didn’t know the importance of the subscription key and, indeed, I don’t know yet, but the Play Store says that this new key is not the original one and doesn’t accept it. How can I create a new subscription key and get the Play Store to accept it?

I haven’t published the game yet, so I guess I can create a new key, right?