installed but "command is not available"

[3Dietrich]

in VSCode I found "openscad-format" v1.0.1 as a possible openscad formater. Installed and.. an error (on both Catalina and BigSure): "The 'openscad-format' command is not available. Please check your openscad-format.executable user setting and ensure it is installed."

I don't exactly know what it expects from me, both settings seem to be normal ok, I tried to (re)install it by following requirements openscad-format but I have no "npm" installed - so I pressed the link for npm - what showed almost the same page.. wtf Watching https://www.npmjs.com/ (what offers npm?) doesn't bring me to a result, it's about JavaScript and I need to sign up to get anything.. common.. I wanted to install an openscad formatter, not bying an abo for a tool for a tool for installing the formatter! Since this formatter seems the only openscad format I'm bound to it, or I have bad luck.

long story short: What is the reason that it is installed but not available?