How to get free SSL certificate
If you just activated Really Simple SSL, and saw the notice “Possible certificate issues detected”, please check your certificate by entering your site here: https://ssllabs.com/ssltest. If you don’t get an A rating when you scan your site, you probably don’t have a valid SSL certificate yet. A valid SSL certificate is required for Really Simple SSL to work.
Most hosting providers these days offer a simple way to install an SSL certificate. Please refer to your hosting company for information on how to do that. A lot of hosting providers offer the option to install a let’s free encrypt SSL certificate.
If the hosting provider does not offer this possibility, you can also try to add a free SSL certificate with SSL Zen.
If your hosting package has cPanel, you can easily add a free SSL certificate with the SSL Zen plugin. This plugin allows you to generate a free Let’s Encrypt certificate. A Let’s Encrypt certificate is a free SSL certificate.
Requirements:
- cPanel access with the TLS/SSL Manager module enabled
- FTP/file manager access
How to install a free SSL certificate on your cPanel hosting environment
The first step is to check if your hosting environment supports cPanel.
The easiest way to check this is to navigate to www.yourdomain.com/cpanel. Most hosting providers allow you to access cPanel by adding /cPanel to your domain. Another option is to check for cPanel in your hosting environment. Most hosting providers have a link to your cPanel environment.
Install the SSL Zen plugin by navigating to the ‘Plugins -> add new’ menu. Note that the free SSL Zen plugin requires a manual certificate renewal every 90 days. SSL Zen Premium (lifetime license) allows the SSL certificate to renew automatically. We recommend to do this as setting up an automatic renewal can prevent certificate issues in the future.
Installing and using SSL Zen

Once installed, navigate to the SSL Zen wizard:

Make sure to include the www-prefixed version to and check if the contact details are correct. Next, check the box below the contact details to agree to the terms and conditions. Once checked, press the next button in the top right part of the wizard.
On the next page, you will find instructions to create a directory and upload two files to it. Luckily SSL Zen has great documentation, making the entire process relatively easy.

After you have placed the files in the .well-known/acme-challenge/ folder you can continue to step 3.

You should now have received the certificate files per e-mail. Now follow the step by step guide to install the SSL certificate on your server. Once that is done, SSL can be activated with Really Simple SSL!
If you want to renew your SSL certificate automatically, have a look at The SSL Zen lifetime license. For just $29/year your SSL certificate will be renewed automatically, indefinitely.
Source – Mike Really Simple SSL