If yout have problems for check ruby versions on your ubuntu + zsh, just put this in your terminal and set path for your rbenv
$ echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.zshenv
$ echo 'eval "$(rbenv init -)"' >> ~/.zshenv
$ echo 'source $HOME/.zshenv' >> ~/.zshrc
$ exec $SHELL
Thank you
Thanks!!