Private registries with authentication require a special configuration since npm version 9.

In npm version 6 the npmrc looks like this:

registry = https://some.private.registry/api/npm/my-npm-repo/
_auth = 3489034someHashwfhdsd87

In npm version 9, the key _auth must be mapped to a specific registry:

registry = https://some.private.registry/api/npm/my-npm-repo/
//some.private.registry/api/npm/my-npm-repo/:_auth = 3489034someHashwfhdsd87

npm version 8 is still compatible with the old configuration format, but a warning appears in the logs:

npm WARN config `_auth`, `_authToken`, `username` and `_password` must be scoped to a registry. see `npm help npmrc` for more information.

The nodejs-plugin currently lacks support for the new configuration format.