Deny client syncing for non admin users?

How can I configure this app to disallow all file access through a syncing client for non admin group users?

My server is a bit slow and I would prefer if the majority of users would only use the web-interface.

Thanks for the help!

I looked here already: https://docs.nextcloud.com/server/10/admin_manual/configuration_files/files_access_control.html
But that doesn’t seem to explain it, but I guess that should be possible with this app?