Run these.
sudo apt update -y
sudo apt upgrade -y
sudo apt install gcc make libssl-dev libreadline-dev zlib1g-dev libsqlite3-dev libyaml-dev
git clone https://github.com/rbenv/rbenv.git ~/.rbenv
~/.rbenv/bin/rbenv init
eval "$(~/.rbenv/bin/rbenv init - zsh)"
mkdir -p "$(rbenv root)"/plugins
git clone https://github.com/rbenv/ruby-build.git "$(rbenv root)"/plugins/ruby-build
rbenv -v
rbenv install 3.3.5 --verbose
rbenv global 3.3.5
ruby -v