How to get a UCS 5.0-x version?

I am trying to install a backup server to my standard UCS which is still on 5.0-9 since we use nextcloud which is unavailable on 5.2. In order to achieve this I need an installable version of UCS 5.0-x. Where can I get this ? I still have an old 4.4 version on a stick but I don’t consider it a good idea to start with this …

Any help is appreciated - Martin

Martin,
how about here:
https://updates.software-univention.de/download/ucs-cds

You’re my man - thx, Martin