./letsencrypt.sh request_single your.hostname.com 4096which will also install the new cert/key/ca files in all respective global places for apache, dovecot, exim, ftp, and DirectAdmin.
NOTE The hostname value, eg: your.hostname.com must match the “servername” value set in the directadmin.conf, or it will not be in hostname mode, but User domain mode instead.
You must then turn on SSL in DA and tell DA to use the carootcert, as well as force the hostname for SSL:cd /usr/local/directadmin/conf
./directadmin set SSL 1
./directadmin set carootcert /usr/local/directadmin/conf/carootcert.pem
./directadmin set force_hostname your.hostname.com
./directadmin set ssl_redirect_host your.hostname.com
service directadmin restart