./bin/sanitycheck.js How to use ?

Hi

I am following the guide - https://www.espruino.com/Bangle.js+App+Loader
I am trying to run ./bin/sanitycheck.js

Alas I do not have too much experience of nodejs. I have now installed, nodejs but ...

$ bin/sanitycheck.js 
internal/modules/cjs/loader.js:818
  throw err;
  ^

Error: Cannot find module '../webtools/heatshrink'
Require stack:
- /home/bms/BangleApps/bin/sanitycheck.js
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:815:15)
    at Function.Module._load (internal/modules/cjs/loader.js:667:27)
    at Module.require (internal/modules/cjs/loader.js:887:19)
    at require (internal/modules/cjs/helpers.js:85:18)
    at Object.<anonymous> (/home/bms/BangleApps/bin/sanitycheck.js:7:18)
    at Module._compile (internal/modules/cjs/loader.js:999:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)
    at Module.load (internal/modules/cjs/loader.js:863:32)
    at Function.Module._load (internal/modules/cjs/loader.js:708:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:60:12) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [ '/home/bms/BangleApps/bin/sanitycheck.js' ]
}

$ ls webtools/
$

webtools is empty

This - https://github.com/espruino/BangleApps/blob/master/bin/README.md suggests

You should also check out https://github.com/espruino/EspruinoAppLoaderCore/tree/master/tools (available in core/tools in this repo) - this contains tools for handling languages, as well as a command-line based app loader

I tried to do this clone this repository and can get the tools into webtools, but I am doing something wrong and can get his correct.

This tarvis runs suggests - https://github.com/espruino/BangleApps/actions/runs/11096198234/job/30835784505?pr=3595#step:2:496
git submodule sync is the answer ?
(No tried)

Any help on were I am going wrong would be great.

Regards,
Brendan