Renewing a certificate is usually done by using the command certbot renew;
Please upgrade your CentOS, CentOS 6 is not receiving any maintainance updates for more than 2 years already;
Certbot has a DNS plugin for dnsmadeeasy (User Guide — Certbot 2.6.0 documentation), it would be better to use that plugin instead of using the manual plugin, which cannot be automated;
certbot-auto is deprecated and removed for some years now. Please don't use it any longer, but upgrade to a better method of installing Certbot;
your DNS resolving capabilities are malfunctioning, resulting in the error shown.
Also, the domain m.com is a IANA reserved domain. I'm pretty sure your email address doesn't work; is it a fake one? If so, you should have used the --register-unsafely-without-email option if you didn't want to specify an email address.