I'm making an app using Flutter and firebase which allows the user to create an account and log in and out. Can Firebase handle 2 different users with the same username? Do I need to add something to prevent this from happening? Will Firebase know which user is trying to log in, by looking at the different passwords? (my App doesn't take the email address of the users, just their username)
eg.:
username(email): Jack ; password: awesome
username(email): Jack ; password: summer