Certbot is a free and open-source utility mainly used for managing SSL/TLS certificates from the Let’s Encrypt certificate authority.

Installing Certbot
Most Linux distributions provide certbot in their official repositories. Below are installation instructions for widely-used platforms.

Debian and Ubuntu:

apt update
apt install -y certbot

Fedora and CentOS:

dnf install -y certbot

Or

yum install -y certbot 

 
Arch Linux:

pacman -Sy certbot
FreeBSD:

pkg install py36-certbot
OpenBSD 6.0 and later:

pkg_add certbot
MacOS (homebrew required):

brew install letsencrypt