Почему мой сертификат ssl самоподписан?

Я выполнил следующие шаги, чтобы установить ssl-сертификат на веб-сайт; https://www.digitalocean.com/community/tutorials/how-to-secure-apache-with-let-s-encrypt-on-centos-7. Однако веб-сайт по-прежнему не пользуется доверием, поскольку сертификат самозаверяющий. Я не могу понять, что делаю не так.

Centos7 Apache

Вывод после запуска sudo certbot --apache -d climatedata.ibs.re.kr -d www.climatedata.ibs.re.kr

    Saving debug log to /var/log/letsencrypt/letsencrypt.log
    Plugins selected: Authenticator apache, Installer apache
    Starting new HTTPS connection (1): acme-v01.api.letsencrypt.org
    Obtaining a new certificate
    Performing the following challenges:
    http-01 challenge for climatedata.ibs.re.kr
    http-01 challenge for www.climatedata.ibs.re.kr
    Waiting for verification...
    Cleaning up challenges
    Created an SSL vhost at /etc/httpd/sites-available/climatedata.ibs.re.kr-le-ssl.conf
    Deploying Certificate to VirtualHost /etc/httpd/sites-available/climatedata.ibs.re.kr-le-ssl.conf
    Enabling site /etc/httpd/sites-available/climatedata.ibs.re.kr-le-ssl.conf by adding Include to root configuration
    Deploying Certificate to VirtualHost /etc/httpd/sites-available/climatedata.ibs.re.kr-le-ssl.conf

    Please choose whether or not to redirect HTTP traffic to HTTPS, removing HTTP access.
    -------------------------------------------------------------------------------
    1: No redirect - Make no further changes to the webserver configuration.
    2: Redirect - Make all requests redirect to secure HTTPS access. Choose this for
    new sites, or if you're confident your site works on HTTPS. You can undo this
    change by editing your web server's configuration.
    -------------------------------------------------------------------------------
    Select the appropriate number [1-2] then [enter] (press 'c' to cancel): 2
    Enhancement redirect was already set.
    Enhancement redirect was already set.

   -------------------------------------------------------------------------------
    Congratulations! You have successfully enabled https://climatedata.ibs.re.kr and 
    https://www.climatedata.ibs.re.kr

    You should test your configuration at:
    https://www.ssllabs.com/ssltest/analyze.html?d=climatedata.ibs.re.kr
    https://www.ssllabs.com/ssltest/analyze.html?d=www.climatedata.ibs.re.kr
    -------------------------------------------------------------------------------

Я все еще новичок в этом, пожалуйста, дайте мне знать, какие журналы (если есть) я должен предоставить, и я добавлю их в этот пост.