From Newsgroup: gnu.emacs.help

I have some elisp that sets up menu buttons like this:

(define-key-after ;Save
(lookup-key global-map [menu-bar]) ;map is the "key" named menu-bar
[my-save] ;this button's key name
'(menu-item "Save" save-buffer ;label, function
)
'(lookup-key menu-bar [ff]) ;put this button after "key" ff
)

The "ff" is a name I gave to a preceding button.

In Windows emacs 28.2 this works.
In ubuntu emacs 29.1 this fails. It compiles, but depressing mouse 1 on the button produces only a small, empty window.

In emacs 28.2 and 29.1, global-map has entries for my buttons.

Emacs 29.1 has deprecated define-key-after. It requires keymap-set-after. keymap-set-after rejects "ff" and "my-save" as key identifiers.

I cannot figure out how to name the menu-button "key" for keymap-set-after.
How do I do that?
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