The database to authenticate against. If the user is registered on only one database; the user will be automatically authenticated against the correct database and this parameter can be omitted (the database name is returned in the LoginResult object). If the user is registered in multiple databases; the database value for the particular database you are trying to authenticate against must be provided.
password
The user's Geotab password.
userName
The user name (typically an email address) that identifies the user being authenticated.
Return value
A LoginResult object. It contains the Credentials property that can be used for further API calls.