I'm trying to configure github with my macOS system. I use iTerm and zsh. When I try to generate a new ssh key according to the instructions from the https://help.github.com/en/github/authenticating-to-github/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent#generating-a-new-ssh-key I get an error "zsh: command not found: $". Please help.