The entry-URL to Authenticate is https://URL-TO-LIAM3-Client/liam3_Client_login.php This is important and has to be defined in every Sub-System. For Example in the project SQMS, the config should look like this:
define('API_URL_LIAM', 'http://localhost/liam3-client/liam3_Client_login.php'); // URL from Authentication-Service -> returns a JWT-Token
define('AUTH_KEY', 'xxxxxxsecretkeyxxxxxx'); // Shared AuthKey which has to be known by the Authentication-Service