Need help on agent service installation for Aras Innovator separate server installation in cluster env

I am setting up innovator 12.3 in cluster environment with load balancer sitting in front of multiple innovator instances.

Do I need to set up separate agent service for each innovator instance that are under the load balancer or only one agent service would suffice?

If one agent service works for all the instances of innovators under load balancer, which URL, agent service needs to point to ? Load balancer URL ?

 Any hints or references  ? Thanks, Gautam K