Where's the link button?

I’m afraid that I’m finding it frustratingly difficult to master even the basics of the Key Editor. I’ve tried finding help in Dorico videos, manuals, forum discussions, version history etc. but there are simple questions that I can’t find the answers to. For example, everywhere I look in the documentation there is mention of a ‘link button’ in the lower zone when using the editor. It’s supposed to sit to the right of the Playing Techniques button, but this is what’s on my screen:

Have things changed since the documentations were created? I’m on version

The link button was indeed removed in Dorico 4.3. The documentation for the Key Editor in the Dorico 4.3 Version History is designed to be complete, and can be read from start to finish as a complete guide to how to work with it, superseding the information later on in the Version History. So I suggest you read pages 14–30 in this PDF, and hopefully things will be a bit clearer afterwards:

Many thanks, Daniel. I had accessed the Version History and read the section you refer to. However, since the link button (or the removal of it) isn’t mentioned in those pages (though its very absence in the screenshot of the toolbar should have answered my question), I decided to search for the term ‘link button’ and was taken to page 103, where it is indeed described. My big mistake was not to notice - even though the document is called ‘Version History’ - that that page is part of the description of Dorico 4.0, a clue which I really should have spotted.

Well, perhaps it would be better if we actually removed the superseded information, though that’s not normally our practice. And of course the absence of the Key Editor from the Operation Manual is also less than ideal, but Lillie is hard at work on getting that done, so hopefully it won’t be too long before the manual itself can become the single source of truth about the Key Editor.