Here is manual for the web interface, the clients, as well as a bit of technical background around Seafile:
kuno will be disabled in the long term, all accounts shall be moved to the new server (wolke.pkm.physik.tu-darmstadt.de)
The reason is that kuno uses the old authentication service from AG Vogel, a switch is not possible.
You can access Seafile via the Kuno web frontend (Old)/Wolke web frontend (New) or you can use clients on Android, Linux, Windows and iOS.
Groups in Seafile are independend from the groups of the account server! You can create a group and put your members in there. They can only be added if they have logged in once, otherwise the system won't know about the user.
sudo wget https://linux-clients.seafile.com/seafile.asc -O /usr/share/keyrings/seafile-keyring.asc
sudo apt update
sudo apt install -y seafile-gui