Authenticate and install key/cert pair into Redis hosts (authentication reverse proxy):

certbot run -d example.com -a letsencrypt-redis:auth --letsencrypt-redis:auth-redis-hosts 192.168.1.1,192.168.1.2 -i letsencrypt-redis:installer --letsencrypt-redis:installer-redis-hosts 192.168.1.1,192.168.1.2 -n --force-renewal

Install key/cert pair into local Redis

certbot run -d example.com -a standalone -i letsencrypt-redis:installer -n --force-renewal