How to add Free SSL for my WP Site Other than CloudFlare?

But don’t try free trial certificates, as they won’t be trusted by all browsers without a certificate chain! Try instead, but you need to generate a Private Key and CSR from the “SSL/TLS” section of the Control Panel for your domain compiling all the fields while generating the CSR, check “I do not want to use default parameters (CSR, Admin and Tech contacts)” and “I have your own CSR” and put the generated CSR in the field, compile all details, and select the Mail Method (it needs your domain to have the MX record set to and a mail account that is at least named admin@yourdomain) to verify your identity. After that you have to install the certificate, and you can do that without any problem by following these steps and copying only the certificate, not the CSR or the certificate chain. After 90 days, you can repeat the steps again.