Jitsi meetに無料証明書Let’s Encryptの登録でTimeout during connect (likely firewall problem)

事象内容

下記のLet’s Encryptを登録するコマンドを実行し、Emailアドレスを求められるので入力すると

$sudo /usr/share/jitsi-meet/scripts/install-letsencrypt-cert.sh

こんな感じのエラーが発生しました。

ドメインをhttp://example.comと表記してますので各自の環境で読み換えて下さい。

Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator webroot, Installer None
Obtaining a new certificate
Performing the following challenges:
http-01 challenge for csiinc.ddns.net
Using the webroot path /usr/share/jitsi-meet for all unmatched domains.
Waiting for verification...
Cleaning up challenges
Failed authorization procedure. example.com (http-01): urn:ietf:params:acme:error:connection :: The server could not connect to the client to verify the domain :: Fetching http://example.net/.well-known/acme-challenge/BZWdjGHSRKK3UUrosMKh8Cw9DDO-GF8hXwH182S0bHU: Timeout during connect (likely firewall problem)
IMPORTANT NOTES:
 - The following errors were reported by the server:
   Domain: csiinc.ddns.net
   Type:   connection
   Detail: Fetching
   http://example.com/.well-known/acme-challenge/BZWdjGHSRKK3UUrosMKh8Cw9DDO-GF8hXwH182S0bHU:
   Timeout during connect (likely firewall problem)
   To fix these errors, please make sure that your domain name was
   entered correctly and the DNS A/AAAA record(s) for that domain
   contain(s) the right IP address. Additionally, please check that
   your computer has a publicly routable IP address and that no
   firewalls are preventing the server from communicating with the
   client. If you're using the webroot plugin, you should also verify
   that you are serving files from the webroot path you provided.

試したこと

下記のエラーからファイアーウォールが怪しいと思い設定を確認するが、特に怪しいところは見つからず。

Timeout during connect (likely firewall problem)

解決策

下記の手順で無事登録が完了できました。

$ sudo apt install certbot
$ sudo sed -i 's/\.\/certbot-auto/certbot/g' /usr/share/jitsi-meet/scripts/install-letsencrypt-cert.sh
$ sudo ln -s /usr/bin/certbot /usr/sbin/certbot
$ sudo /usr/share/jitsi-meet/scripts/install-letsencrypt-cert.sh