[BUG] Unable to download tarball of private packages

Is there an existing issue for this?

• I have searched the existing issues

This issue exists in the latest npm version

• I am using the latest npm

Current Behavior

I'm unable to use the npm pack command to download the the tarball of npm packages I have published on my private GitLab package registry:

npm ERR! code E404
npm ERR! 404 Not Found - GET https://gitlab.<...>/api/v4/projects/87/packages/npm/@<...>/-/@<...>-2.1.1.tgz
npm ERR! 404 
npm ERR! 404  'https://gitlab.<...>/api/v4/projects/87/packages/npm/@<...>/-/@<...>-2.1.1.tgz' is not in this registry.
npm ERR! 404 This package name is not valid, because 
npm ERR! 404  1. name can only contain URL-friendly characters
npm ERR! 404 
npm ERR! 404 Note that you can also install from a
npm ERR! 404 tarball, folder, http url, or git url.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/<...>/.npm/_logs/2022-07-19T19_07_44_458Z-debug-0.log

When I first do a npm install -g before, it downloads the package on cache, using the credentials I set on the .npmrc file, and then the npm pack command works as expected afterwards.

Expected Behavior

Directly download the tarball of private packages using npm pack, considering the credentials set on .npmrc file, without the need of executing the npm install -g command before to save it on cache.

Environment

• npm: 8.14.0
• Node.js: v16.14.0
• OS Name: Kubuntu 22.04

Reproduce the failure with npm 8.14.0 and Node.js 16.14.0 using npm pack against the private GitLab package registry, with credentials configured in .npmrc. Compare this with npm install -g, which populates the cache, and trace the package-fetch path involved. Done means npm pack downloads the private tarball directly without requiring a prior install.