VSC -- How to Add File Extensions to Show in Explorer

How Do I Configure Visual Studio Code (VSC) Explorer to Show Files with other File Extensions?

I want to use .scpt as the file extension for some of my JavaScript files -- JXA files actually. I want VSC to treat all of them just like .js

I created a test.scpt file and clicked on the file type at the bottom, and changed it to "JavaScript". But other .scpt files in the same folder do NOT show in the VSC Explorer Panel.

How do I change this?

I am extremely frustrated with the VSC settings system. :frowning:
I have done extensive searching, and found lots of examples, but none of them correspond to what I am seeing in VSC.

For example, I found this:

// .vscode/settings.json in workspace

  "files.associations": {
    "*Container.js": "javascriptreact",
    "**/components/*/*.js": "javascriptreact",
    "**/config/routes.js": "javascriptreact"

But I can't find this in VSC.

I have read VSC help that says you can add/change file extensions, but it never shows how.

This should NOT be this hard.