[root@b1ix ~]# wget -qO- https://raw.githubusercontent.com/creationix/nvm/v0.34.0/install.sh | bash
=> Downloading nvm as script to '/root/.nvm'

=> Appending nvm source string to /root/.bashrc
=> Appending bash_completion source string to /root/.bashrc
=> Close and reopen your terminal to start using nvm or run the following to use it now:

export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"  # This loads nvm
[ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"  # This loads nvm bash_completion
[root@b1ix ~]#
[root@b1ix ~]# nvm install v11.3.0
Downloading and installing node v11.3.0...
Downloading https://nodejs.org/dist/v11.3.0/node-v11.3.0-linux-x64.tar.xz...
######################################################################## 100.0%
Computing checksum with sha256sum
Checksums matched!
Now using node v11.3.0 (npm v6.4.1)
Creating default alias: default -> v11.3.0
[root@b1ix ~]# node -v
v11.3.0
[root@b1ix ~]# npm -v
6.4.1