FreeBSD Install sudo Command To Execute Commands

Originally published at: https://www.cyberciti.biz/faq/freebsd-install-sudo-command/

I have recently started to managing FreeBSD server along with Ubuntu Linux. However, sudo command, always shows me the following error:

zsh: command not found: sudo


How do I install sudo command under a FreeBSD 9.x/10.x/11.x/12.x system?