Reference external IP in new deployment

Hi! I have a web app running in a pod and created a Service Type LoadBalancer so it gets an external IP and is publicly accessible on port 80. Now I’m trying to create a new deployment, where one of the environment variables takes an http endpoint (my previously created service) to interact with. Is there a way for my new deployment to lookup that endpoint and set said environment variable dynamically upon each deploy? I’m trying to avoid hardcoding the endpoint each time.

Thanks in advance!

Cluster information:

Kubernetes version: 1.16.13-gke.401
Cloud being used: Google