How to fix not secure error on your domain or How to install Free SSL Letencrypt over AutoSSL?
Kindly follow the step
Login to your cPanel > SSL/TLS Status > Run AutoSSL
It will install the Free SSL from Letsencrypt.
Please allow some time as it needs to verify your DNS and other settings before the installation
Make sure your domain has been pointed to our Server IP/Nameservers/DNS so it will install the SSL.