Npm publish on Cloud9 doesn't work

I am doing the Manage Packages with npm course and going through the how-to-npm.

Running npm-publish gives the following error:

npm ERR! need auth auth required for publishing
npm ERR! need auth You need to authorize this machine using npm adduser

I run npm adduser and login with my npm user details and get the following error. Looks like the login didn’t work but it works fine on the npm site:

npm ERR! 404 missing : -/user/org.couchdb.user:ashnita

Also, npm rm gives the following warning:
npm WARN uninstall not installed in /home/ubuntu/.nvm/versions/node/v4.6.1/lib/node_modules: “test-package”

Any advise?