Terminating Istio container for job with multiple business containers

Hi everyone, I have the following use case -

I want to launch a K8 job which has an istio container (as a sidecar) and multiple business containers. These business containers depend on istio for communications to and from outside entities and thus cannot terminate before the business containers terminate. The way we terminate the istio container is by sending a /quitquitquit signal to istio after the business logic is done.
My problem is that I want the last container to to call make this call to istio so that any business logic processing is not affected.
Any suggestions on what would be the best way to do this?

Cluster information:

Kubernetes version: 1.20
Cloud being used: Amazon Web Services
Host OS:

NAME="CentOS Linux"
VERSION="7 (Core)"