If you have already installed a self-signed or paid Comodo SSL certificate on your domain, you can always change it to a 'Let's Encrypt' certificate in the panel.
- Navigate to the Secure Hosting page.
- To the right of your domain, click the 'Change' link.
- Choose the option to add a 'Let's Encrypt' certificate.
- Check the box to agree to the terms of service.
- Click the Save changes now! button.
In a few hours your new certificate is automatically installed.
Forcing your site to load HTTPS be default
Even after you have added the SSL certificate to your site, visitors will not be able to use it unless they manually type in 'https' before your domain name. This defeats the purpose of adding it in the first place since the certificate is meant to protect all of your website traffic.
There are several ways to fix this. View the following article for instructions on how to create a configuration file to redirect all visitor traffic to the secure version of your URL (https).
Redirecting to the HTTPS version of your URL only works for the same domain. This means that you can only redirect from http://example.com to https://example.com.
Is it NOT possible to redirect to a different domain. For example: http://example1.com to https://example2.com would not function with a 'Let's Encrypt' certificate.