The installation of a UCS domain controller slave as school domain controller can be done manually as described in the UCS@school administration manual.
If an automatic installation is required, this can be done using the script referenced here. The script requires the installation of a UCS domain controller slave that is part of the domain (joined). It is recommended not to select any additional software when installing the UCS domain controller slave. The script installs the UCS@school app and also performs the configuration.
The script can be downloaded as follows:
wget -O school-slave-installer.py 'https://raw.githubusercontent.com/univention/ucs-school/4.3/ucs-school-umc-installer/SDB-tools/school-slave-installer.py'
Afterwards, it can be started either interactively or non-interactively on the UCS domain controller slave, for example:
python school-slave-installer.py python school-slave-installer.py -q -u Administrator -p univention -o school1
--help shows the help.