making catalog referenced files managed files

In the article working with managed and referenced files I read: "h simply drag and drop any images onto the Catalog icon in the Folders area. In the example below, it will move the file from the external storage to the catalog file itself."

Wel In the library in capture one there is only an icon of a catalog folder. If I want to drag and drop the referenced folder into it, nothing happens. What am I missing. Working in C1 23