File access control - only upload?

Hi. I want to have two users - admin and upload user.
Upload user can upload data on server, but he cannot open or download any data from server - even that data, which I through him upload on server.
Admin can of course work with all the data.

When I set for “upload user” the resctriction on data , if I put him to the group with that resctriction, I am unable to even upload any data.

I need that “upload user” just to upload any type of data without any possibility to download from the server. Any advice, how to set that? Thanks.

Normally you only use an upload share. If not everybody should upload you can use a password for the upload share. You do not need a user.

Like I will put to every file a password? Or how do you mean?

No. You share only a directory for upload. But there is only on directory in my case.