If you no longer have access to the Facebook, Google, or Apple account associated with your Atlas Earth account, you will not be able to use that account to log in to Atlas Earth. Your Atlas Earth account is tied to the Google, Facebook, or Apple account you first used to open the game. Using a different login will create a new account. This means you will not be able to log in to the game.

Players are not able to update their login option at present. We advise against deleting or changing the Facebook, Google, or Apple account associated with your Atlas Earth account to avoid losing game access. If you have deleted the account associated with your Atlas Earth account, or your account has been locked, hacked, or is otherwise unavailable, your Atlas Earth account will remain active in the game and continue earning rent, but it will no longer be accessible.

Check this article for instructions on how to log in using an SMS code.