To use Lets Encrypt certbot command to install certificate to work with AWS Lightsail Wordpress instance
sudo certbot certonly --webroot -w /opt/bitnami/apps/wordpress/htdocs/ \
-d domain1.org
To add new domains to certificate
sudo certbot certonly --webroot -w /opt/bitnami/apps/wordpress/htdocs/ \
--expand -d domain1.org,www.domain1.org,domain2.edu,domain3.org