What is the keystroke for inserting a single measure on MacOS?

In MS3 (on MacOS) I can press **i **to insert a measure before the selection.

I'm trying to adapt to MS4, but:

   •  the Handbook says "press the ins key."

   • the tool tip shows: Command [?]

Regarding the handbook, the current Mac keyboards don't have a key labeled ins or insert. It was replaced many years ago with the fn key. Some sources say that the fn key will function as the insert key, but that hasn't proved fruitful in MS4.

And clearly there's something amiss with the Add>Measures tooltip.

I haven't found a functional keystroke for inserting a single measure on MacOS, and I'm just not a menu type of guy.

Any suggestions ... short of creating my own tooltip? I like to keep things standard when I can.