first_name (str): The first name of the user to add to the organization.
last_name (str): The last name of the user to add to the organization.
email (str): The email of the user to add to the organization.
password (str, optional): The password of the user to add to the organization. If omitted, an unusable password is set.
role (str): The role of the user to add to the organization. (global admin, application admin, user)