QWC2 build pipeline problems

I am trying to build the qwc2 demo app from https://github.com/qgis/qwc2-demo-app on a windows machine. I have a working QGIS server and a customized "themesConfig.json".

After "git clone" I do "yarn install" like the documentation suggests, but I get some deprecation warnings:

Do I have to use a specific node or yarn version to compile qwc2?

If I ignore the warnings and continue with "yarn start" the process stops with an error "Missing package ‘UUID’":

I tried to add the package "uuid": "8.3.2" to qwc2package.json, did "yarn install" and "yarn start" but then it complained about another missing package: "glob".

If I add this package, there are some other missing packages until it complains about missing "chokidar". At this point adding it to packages.json doesnt work and I am stuck.

I am new to npm/yarn.

What am i doing wrong here?

Do i need some special switch to let yarn pull all required dependencies on its own?

Or is there a problem in the qwc2 repository?