To spell it out, the feature you link to does not provide any new options in the editor.
It modifies the
/nodes admin http endpoint to support a
url parameter that can be used to provide a installation source url for a node. Within the editor, the catalog format has also been updated so entries in the catalog can include such a url.
However - this doesn't mean you can now just pass a URL to the
/nodes api by itself - you still need to provide the module name that will be installed from that URL.
Coincidentally, I opened a design PR yesterday to consider adding the ability to upload a node's tgz file directly via the
/nodes api - as well as the UI changes to the palette manager so it can be done fro the editor - https://github.com/node-red/designs/pull/35
Whilst writing that, it became obvious that we lacked the ability to do what you're asking here - provide a way for the user to provide a url directly in the UI. That may get rolled into the above design as well.
As an aside, the
/nodes docs haven't been updated to reflect the support for url - I need to make sure PRs that modify the admin API also drive issues to be raised against the docs so things like this don't get overlooked.