There is a JW Lua script for this on the French forum "Finalisons" (register as a member first), developed by chris. English interface available. Shape expressions. Range is variable, 2 octaves max. Fingerings optional.
From what I can see, you have installed JW Lua correctly on your Mac.
There are 2 more steps (assuming you have downloaded the script file "Keyboard diagrams.lua") :
1) place the "Keyboard diagrams.lua" file into the JW Lua folder (which contains jwlua64.bundle)
2) Via the plug-ins menu of Finale, launch JW Lua, then select Manager (if not selected), under "Menu groups", click on the "Menu" item, and below, under "Items in Group" -> "New". Locate the "Keyboard diagrams.lua" script to load it.
Relaunch Finale. The new script should be visible in the JW Lua folder (Plug-ins menu). You can now use it. There is a button in the bottom left corner to select the English interface.
P.S.: for the future, you should install RGP Lua, and create a similar subfolder. RGP Lua is the new Lua environment, currently developed by Robert Patterson. It can use most of the JW Lua scripts (if a copy is placed in the RGP Lua folder and loaded into RGP Lua), and many new ones.
I did that, and still empty JW Lua folder when I open Finale. BTW, that's the folder I made myself and named it JW Lua. I have MacBookPro M1 14". I also tried to start Finale with Rosetta mode, but it says this plug-ins is not supported.
Now that you mention Mac M1 (Monterey and Finale 27, I suppose, please add all these infos to your profile, it helps narrowing down the problems), all the JW plug-ins (and JW Lua is one of them) are not native.
So Rosetta is the only way to use them.
1) In the JW Lua (Manager selected) window, do you see "Diagrammes ..." at the bottom, under Items in group ?
2) Did you restart the Mac ?
3) What is the exact error message you get ? Is it about authorization ?
P.S. : Other JW plug-ins (also non native) seem to work if Finale 27.2 (your version ?) is launched in Rosetta mode.