Hugo 115.1 and PostCSS do not work well enough to be usable

Attempts to use something innocuous like:
npm install postcss postcss-cli autoprefixer generate the following error in the pipeline:

++ echo '$ npm install postcss postcss-cli autoprefixer'
$ npm install postcss postcss-cli autoprefixer
++ npm install postcss postcss-cli autoprefixer
npm ERR! code 1
npm ERR! path /builds/pages/docs/node_modules/hugo-extended
npm ERR! command failed
npm ERR! command sh -c node postinstall.js
npm ERR! ✔ Hugo installed successfully!
npm ERR! ✖ Hugo installation failed. :(

Those last two lines make me wonder if someone from SAP wrote this code.
I need to install these globally. I don’t know why, but it seems to be so…