Check this video out - it will explain a bit more - the UDC is only to bring in user metadata to the repository - it does not provide any authentication: Qlik Sense Platform - Qlik Management Console User Directory Connector - Part 5
By default user authentication is handled via Windows operating system local / domain security. So you use the id and password that is in your windows system. You then setup user / login access to the system with the QMC.
You might want to check out the whole series available here: https://community.qlik.com/docs/DOC-7144#qmc
Available from this index: New to Qlik Sense Enterprise Server Videos
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