I can't. It's incredibly wasteful time and resource-wise, and ties your development process to third-party providers (and your ISP), which fall over often enough in practice.
It's a good practice to have a local cache of all the third-party dependencies you use, available to both developers and CI infrastructure.
We have that, it's called Java and .NET, but apparently solved problems aren't interesting anymore.
For a distributed company with developers from all over the globe the "local" here doesn't really make much sense. But from my experience with NPM, you download packages on your developer machine once you set up a project, and then only when something really messes up node_modules, which happens once in three months, on average.
You do re-download packages for every build in CI pipeline as you build a docker image from scratch though, and that's when NPM mirror is usually set up.