Insert root certificate in CL installer

I want to install CL on a computer that requires a certain root certificate in order to connect to the internet. The cert is:
I understand that in order for the CL installer to complete successfully, it needs to download a file or two.
Please provide instructions how I can get all this to work.
I can connect to the netfree site in order to get the cert, but that’s the only site I can connect to, until I install the cert.

I saw the following in the documentation. Is this the recommended method, and do I need to refresh the certificate store?

Add (trust) a root CA¶
clrtrust add ~/PrivateCA.pem

The command above will add a root CA certificate located in the ~/PrivateCA.pem file. If the certificate file is not in the PEM format, use openssl x509 command to convert to PEM first. For example:

openssl x509 -in PrivateCA.cer -inform der -out PrivateCA.pem -outform pem

Bump? Is there anyone out there anymore?