How to Install Ruby on Ubuntu 20.04
code:install
sudo apt update
sudo apt install git curl autoconf bison build-essential \
libssl-dev libyaml-dev libreadline6-dev zlib1g-dev \
libncurses5-dev libffi-dev libgdbm6 libgdbm-dev libdb-dev
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(rbenv init -)"' >> ~/.bashrc
source ~/.bashrc
rbenv -v
rbenv install -l
rbenv install 2.6.8
rbenv global 2.6.8
Reference