To get it to work, InDesign needs to be run as an administrator.
So, you’ll need to close InDesign, if it’s open. Locate the InDesign icon (in the taskbar, or in the Start menu) and right-click on it.
There should then appear an option “Run as Administrator.” Click on that.
Now, in the Id-Extras script of your choice, it should be possible to click the About button, check the box that creates the Id-Extras menu, and at this point when you reopen InDesign, the menu should be there!
A bit of a fiddly business, and I really want to revisit the menu mechanism when I get the chance, but, for now, that’s how it’s done!
(Some screenshots here: https://www.id-extras.com/the-new-id-extras-menu/)
Yes. They can be done all in one go, of course. Meaning, launch ID as admin, go through each script adding it to the menu (without restarting ID each time), and then the next time you restart ID they should all be there.