Install LetsEncrypt on Debian with Nginx Server

Install Certbot and its Nginx plugin with apt:

sudo apt install certbot python3-certbot-nginx

Certbot provides a variety of ways to obtain SSL certificates through plugins. The Nginx plugin will take care of reconfiguring Nginx and reloading the config whenever necessary. To use this plugin, type the following:

sudo certbot --nginx -d example.com -d www.example.com