To install SSL go to your Control Panel (cPanel) "SSL/TLS" part.
Enter the "Manage SSL sites" subpart.
Select the domain you need.
You will receive a certificate code after creating the SSL. In the "Certificate (CRT)" field, paste the SSL code from the "domain_name.crt" file.
The certificate code looks like:
In the "Private key (KEY)" field, paste the key code. You received the key code by creating a CSR request.
The key code (KEY) looks like:
Click "Install Certificate".
Certificate installed