Change Kubernetes pods logging
The --v flag is an argument to kubectl and specifies the verbosity of the kubectl output. It has nothing to do with the log levels of the application running inside your Pods.
To get the logs from your Pods, you can run kubectl logs <pod>, or read /var/log/pods/<namespace>_<pod_name>_<pod_id>/<container_name>/ on the Kubernetes node.
To increase the log level of your application, your application has to support it. And like @Jose Armesto said above, this is usually configured using an environment variable.