Only allow users access to shared folders

Hi all,

Is it possible to configure NextCloud (we are running version 13) to only allow users to access and add files to shared folders, i.e. not create personal folders/files outside of folders that have been shared with them.

I have read somewhere this can be achieve by setting a users Quota to 0B. If I do this, when a user logs in they get an error to say their usage quota has been reached, but they still appear to be able to add files to shared folders? If this is the best way to achieve our requirement, can we remote this error message?

Many Thanks,