After import the certificate into IIS, when I navigated away from the Server Certificates window, the certificate would disappear.
I could see the certificate in the server’s Personal Certificate Store using MMC (Microsoft Management Console) but it wouldn’t show up in IIS.

After investigate, I found below solution for this issue:

Save the three portions of the certificate into three separate files (Note: The Intermediate Certificate is optional, if you were not supplied with one, just skip the steps involving it):

privatekey.txt – Copy and paste the contents of the private key including the begin and end lines.
certificate.txt – Copy and paste the contents of the Regular Certificate including the begin and end lines.
intermediate.txt – Copy and paste the contents of the Intermediate Certificate including the begin and end lines.

Upload all these files to a linux server, and run

openssl pkcs12 -export -out certificate.pfx -inkey privatekey.txt -in certificate.txt -certfile intermediate.txt

then import the certificate.pfx into IIS