Can't create custom configuration in deploy/cr.yaml

Hi There,
I’m trying to configure three node cluster in kubernetes like this

. But I was getting an error in the first db pod(cluster-pxc-0) as below and second pod is keep in a CrashLoopBackOff (cluster-pxc-1)

021-11-09T20:14:54.199041Z 0 [ERROR] [MY-000000] [Galera] handshake with remote endpoint ssl:// failed: asio.ssl:337100934: 'certificate verify failed' ( 337100934: 'error:1417C086:SSL routines:tls_process_client_certificate:certificate verify failed')
This error is often caused by SSL issues. For more information, please see:

So I have checked the configuration in the first pod, then I saw , I don’t have my.cnf all the configurations are in node.cnf. I decided to go for custom configuration. I did that according to the documentation as below.

but I couldn’t reflect them in the cluster. there is no my.cnf in my db pods. Could you please help me with this?