Can install but can't run npm packages

I'm having trouble with my node.js/npm setup,

I freshly installed it via the website and it worked fine. It told me to make sure /usr/local/bin/npm has to be in my path and when I run echo $PATH it is in there, so it should be fine.

I can now install packages (tested with npm i webpack -save-dev) the installation works as expected, without any errors.

But when i run webpack all It is giving back is command not found has anyone experienced something like this before?

via Jannik Müller