Switch between your personal library and shared library

Icloud photos help says to do this:

1. Go to icloud.com/photos, then sign in to your Apple Account (if necessary).
2. Click the pop-up menu in the Photos toolbar.
3. The pop-up menu shows Personal Library, Shared Library, or Both Libraries, depending on what you’re currently viewing.

The issue is that I do not get a popup, if i click on library it display my photos. When and how do I get to see this popup?

btw: I've tried 3 different browsers (edge, chrome, safari) on different computers.

Any suggestions?

Daniel