Install Let's Encrypt SSL certificate on Oracle Linux Server

I am trying to install a Let's Encrypt certificate on a Oracle Linux Server 7.6. Since the server does not have a public IP, I had to validate via DNS.I followed the instructions here https://github.com/joohoi/acme-dns-certbot-joohoi and the validation worked and I got the certificate. How do I now install the certificate? I followed instructions online and moved the certificate to etc/ssl/certs and deleted the old certificate. After restarting the machine however the website does not work and I get an error site cannot be reached. I can interact with the server only via SSH.