root@nginx:/etc/nginx/conf.d# certbot certonly --webroot -w /var/www/letsencrypt/ -d rec2.ivoice.online
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 rec2.ivoice.online
Using the webroot path /var/www/letsencrypt for all unmatched domains.
Waiting for verification...
Cleaning up challenges
Running post-hook command: systemctl restart nginx
Failed authorization procedure. rec2.ivoice.online (http-01): urn:ietf:params:acme:error:dns :: DNS problem: NXDOMAIN looking up A for rec2.ivoice.online - check that a DNS record exists for this domain

IMPORTANT NOTES:
 - The following errors were reported by the server:

   Domain: rec2.ivoice.online
   Type:   None
   Detail: DNS problem: NXDOMAIN looking up A for rec2.ivoice.online -
   check that a DNS record exists for this domain