Let’s Encrypt is a certificate authority that provides free SSL certificates, accepted by most browsers. While they provide security and authenticity when accessing your site over SSL, they do not provide end-user warranties or the additional features of commercial certificates.
For a Let’s Encrypt SSL certificate, just login to your hosting Control Panel and click on the SSL tab and then follow the procedure there.
For a RapidSSL or Sectigo, you can purchase online by logging into our Client Area here:
https://clientarea.civihosting.com/
and then there you can place your order.