I'm using OS Catalina and used the solution of Babul Prabhakar. But when I closed the terminal, pod still was unable.
So I put the exports:
$ export GEM_HOME=$HOME/Software/ruby
$ export PATH=$PATH:$HOME/Software/ruby/bin
inside this file(put this command below inside the terminal):
nano ~/.bash_profile
Then save the file, close the terminal and open it up again and type:
pod --version