I've configured the certificate and the certificate chain on the server. But when I perform the certificate validation using the DigiCert diagnostic tool. I got the following error:
The certificate is not signed by a trusted authority (checking against Mozilla's root store). If you bought the certificate from a trusted authority, you probably just need to install one or more Intermediate certificates. Contact your certificate provider for assistance doing this for your server platform.
It appears that the certificate chain in the bundle isn't completed.