How to persist application logs to a file in it's service directory with timestamp ( Istio 1.5)?

I have setup sample demo application on the EKS cluster. I read that we could save the logs via --log_target, but not sure how do you configure this in the virtual service config/yaml file?
Does this log file gets updated everytime there is some sort of processing/action takes place in the service or does it create new file for every request/response to/from a service?
Appteciate any help, thanks in advance.