% zsh --version
zsh 5.8
% path+=("/home/apps/.gem/ruby/2.7/bin/")
% echo $PATH
/usr/bin:/bin:/usr/sbin:/sbin:/usr/X11R6/bin:/usr/local/bin:/usr/local/sbin:/home/apps/ruby/2.7/bin/
% /home/apps/.gem/ruby/2.7/bin/rails27 -v
Rails 6.1.4
% rails27
zsh: command not found: rails27