I use -w instead of webroot
root@monitor.plslogistics.com ~ $ cd /var/www/html
root@monitor.plslogistics.com /var/www/html $ ll
total 4
-rwxr-xr-x. 1 root root 3008 Nov 13 2018 index.php
root@monitor.plslogistics.com /var/www/html $ certbot certonly --webroot /var/www/html -d monitor.plslogistics.com --dry-run
usage:
certbot [SUBCOMMAND] [options] [-d DOMAIN] [-d DOMAIN] ...
Certbot can obtain and install HTTPS/TLS/SSL certificates. By default,
it will attempt to use a webserver both for obtaining and installing the
certificate.
certbot: error: unrecognized arguments: /var/www/html
root@monitor.plslogistics.com /var/www/html $