If you know the URL and the path of a GN4 application, you can run it through ClickOnce even if not listed on the launcher Web page.
For example, if the server URL is http://test.tera.com, and the EdAdmin4 is stored in the applications subfolder, the way to run it is to type the following URL in the address bar of your browser:
http://test.tera.com/applications/EdAdmin4.application