Ubuntu comes bundled with wget, which can retrieve files using HTTP/S and FTP/S protocols. The GitHub page for nvm (https://github.com/creationix/nvm) contains the following command to install it using wget:

wget -qO- https://raw.githubusercontent.com/creationix/nvm/v0.33.11/install.sh | bash

Once installed, restart Terminal to complete the installation. You can check to ensure that the installation was successful by running the following command:

nvm --version