How to modify & replace the built in extension "markdown math" locally in vscode?

I would like to make some small modifications to this built in extension

https://github.com/microsoft/vscode/tree/main/extensions/markdown-math

So I downloaded the code, and run node ./esbuild (following the script in package.json)

And then I did vsce package into a .vsix

However, once I installed it into VSCode, I got errors e.g.

"cannot find ..../.vscode-server/extensions/vscode.markdown-math-1.0.0/out/extension"

I checked in the file system and indeed I didn't have out folders.

Does anyone know what is the correct approach to modify & replace a bundled extension?

Update

After numerous trial & errors, I finally find a partial solution

• Modify markdown-math/notebook/katex.ts
• npm run build-notebook, this would generate notebook-out
• cp notebook-out/katex.js ~/.vscode-server/bin/.../extensions/markdown-math/notebook-out (replace the installed version)

Unfortunately this only works for notebook rendering. I still cannot compile src/extension.ts correctly

Also, I couldn't get access to vscode.workspace.getConfiguration from within notebook/katex.ts as require('vscode') couldn't find vscode module...