sql server can't identify CA Certificate

My company gives a new way to send an email that needs to install CA Cert and enable TLS1.2.
But it can't be identified due to the CA certificate Common Name is not the machine name.
I also try this way(the UPDATED 2 way: SSL Certificate missing from dropdown in SQL Server Configuration Manager. But it still didn't work. I got this error:

The server could not load the certificate it needs to initiate an SSL connection. It returned the following error: 0x8009030e. Check certificates to make sure they are valid. Error: 33566, Severity: 16, State: 1. Found the certificate [Cert Hash(sha1) "xxxxxxxxxx"] in the local computer store but it does not have a private key. Please verify and use a valid certificate.

I use certutil.exe -store My to check it and got the error:

No key provider information Cannot find the certificate and private key for decryption.

So what can I do now? I need to let the CA provider provide a private key. Or are there any other ways?
By the way, I also used it in Oracle. But Oracle doesn't need to change Common Name and private key.