We use the Authentication Plugin available with CakePHP v4 and CakePHP v5 as the foundation for the LDAP integration.
In the past we used the Auth Component which is now being replaced by the Authentication and Authorization Plugins in more recent versions of CakePHP.
The rdcore git code from 15 February onward will have the Authentication plugin included and active.
To add LDAP capability you also need to install the LDAP php library on the system hosting RADIUSdesk.
sudo apt-get install php-ldap