The username of your account to authenticate to KlickTipp.
The password of your account to authenticate to KlickTipp.
The ID of the subscriber within KlickTipp.
(String) Register a custom WordPress hook callback. The value will be called as followed: do_action( $yourdefinedaction, $action_return_data, $request_data )
More available KlickTipp endpoints
To learn more about a specific endpoint, simply click on it.