网站目录方式申请
certbot certonly --webroot -d www.kainonly.com -w /website/www.kainonly.com
泛域名证书申请
certbot certonly --preferred-challenges dns --manual -d *.kainonly.com --server https://acme-v02.api.letsencrypt.org/directory
取消证书续订
certbot delete --cert-name www.kainonly.com