之前在使用 Let’s Encrypt 申請憑證時，因為只有買一個域名，所以開了很多子域名，然後又一個一個申請，結果一堆子域名憑證資料夾。

後來查了，可以使用 `certbot certonly –standalone` 將想要一起申請 SSL 的 域名一起申請

操作如下：

[root@centos]# certbot certonly --standalone -d www.example.cc -d example.cc
Saving debug log to /var/log/letsencrypt/letsencrypt.log

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You have an existing certificate that contains a portion of the domains you
requested (ref: /etc/letsencrypt/renewal/example.cc.conf)

It contains these names: example.cc

You requested these names for the new certificate: www.example.cc, example.cc.

Do you want to expand and replace this existing certificate with the new
certificate?
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(E)xpand/(C)ancel: E
Renewing an existing certificate for www.example.cc and example.cc

Successfully received certificate.
Certificate is saved at: /etc/letsencrypt/live/example.cc/fullchain.pem
Key is saved at:         /etc/letsencrypt/live/example.cc/privkey.pem
This certificate expires on 2025-03-26.
These files will be updated when the certificate renews.
Certbot has set up a scheduled task to automatically renew this certificate in the background.

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If you like Certbot, please consider supporting our work by:
 * Donating to ISRG / Let's Encrypt:   https://letsencrypt.org/donate
 * Donating to EFF:                    https://eff.org/donate-le
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