参考：

https://www.cnblogs.com/michaelshen/p/18538178
https://letsencrypt.org/getting-started/
https://certbot.eff.org/

certbot 选择平台

My HTTP website is running Nginx ON Linux(snap)

按照提示操作如下：

sudo yum install snapd

sudo systemctl enable --now snapd.socket

sudo ln -s /var/lib/snapd/snap /snap

sudo snap install --classic certbot

sudo ln -s /snap/bin/certbot /usr/bin/certbot

sudo certbot --nginx

sudo certbot renew --dry-run