Root CA Cert to validate Server TLS Certificate

Hi, we are planning to use mTLS to authenticate with Temporal Cloud.

In my PoC, I am finding that Temporal Cloud is using a server certificate signed by a public CA. This CA is trusted in my dev machine, but not in the Container where we intend to run our Production code.

Where can I get the official CA cert so that we can set it up - and make our Production code successfully validate Server certificate with mTLS.