npm ERR! 404 happened when I want to install jest

Whan, I want to install Jest this error has happened, I have the latest version of Node,

npm ERR! code E404
npm ERR! 404 Not Found – GET https://registry.npmjs.org/Jest – Not found
npm ERR! 404
npm ERR! 404 ‘Jest@*’ is not in this registry.
npm ERR! 404 This package name is not valid, because
npm ERR! 404 1. name can no longer contain capital letters
npm ERR! 404
npm ERR! 404 Note that you can also install from a
npm ERR! 404 tarball, folder, http url, or git url.