Impossible to install: fatal error

[Gianlo98]

when i run sudo npm install -g homebridge-legacy-plugins i got this error:

npm ERR! git clone [email protected]:github:kevinohara80/elkington Clone nel repository poglio/root/.npm/_git-remotes/git-github-com-github-kevinohara80-elkington-825f44bf'...
npm ERR! git clone [email protected]:github:kevinohara80/elkington Permission denied (publickey).
npm ERR! git clone [email protected]:github:kevinohara80/elkington fatal: Could not read from remote repository.
npm ERR! git clone [email protected]:github:kevinohara80/elkington 
npm ERR! git clone [email protected]:github:kevinohara80/elkington Please make sure you have the correct access rights
npm ERR! git clone [email protected]:github:kevinohara80/elkington and the repository exists.
npm ERR! notarget No compatible version found: elkington@'github:kevinohara80/elkington'
npm ERR! notarget Valid install targets:
npm ERR! notarget ["0.0.1-alpha","0.0.1","0.0.2","0.1.0"]
npm ERR! notarget 
npm ERR! notarget This is most likely not a problem with npm itself.
npm ERR! notarget In most cases you or one of your dependencies are requesting
npm ERR! notarget a package version that doesn't exist.
npm ERR! System Linux 4.14.34-v7+
npm ERR! command "/usr/bin/nodejs" "/usr/bin/npm" "install" "-g" "homebridge-legacy-plugins"
npm ERR! cwd /home/pi
npm ERR! node -v v4.8.2
npm ERR! npm -v 1.4.21
npm ERR! code ETARGET
npm ERR! 
npm ERR! Additional logging details can be found in:
npm ERR!     /home/pi/npm-debug.log
npm ERR! not ok code 0