Please follow the below steps to install free Let's Encrypt SSL.
1. Login to the client area at https://clients.fluccs.com.au
2. Click on Services > My Services > Select the Service.
3. On the Left-Hand side, click on 'Login to cPanel'.
4. Click on Let's Encrypt SSL.
5. You will be forwarded to a page where you can see your domain under 'Issue a new certificate' section.
6. Click on the 'Issue' option on the right side of the domain.
7. In the next screen, you can choose the subdomain to be included in the SSL installation.