do I need a separate loadbalancer/ingress deployment with rke?

Load balancers and ingresses require third-party implementations (by third-party I mean outside upstream Kubernetes) in order to work. Load balancers are usually implemented by a cloud provider but it's possible to set one up on prem with something like MetalLB. By default, RKE will install an NGINX ingress just for ease of use. https://rancher.com/docs/rke/latest/en/config-options/add-ons/ingress-controllers/#default-ingress

metallb says not supported on gcp. I have a gcp instance with nginx running a docker container with http/https access from public with valid DNS. how do I install rancher using the public DNS on this gcp instance