How to access Harbor at prefix/relative URL

Hi I am attempting to install Harbor on an AKS cluster running Istio 1.19.3, at https://<ROOT_URL>/harbor

I am using the official Helm chart and ArgoCD, I have the externalURL set to https://<ROOT_URL> without the harbor path. I am receiving 503 errors when attempting to access, can I place Harbor behind the Istio ingress proxy at a subpath or do I need to use a subdomain?

I disable nginx by setting nginx.replicas to 0. This is the VirtualService I am using:

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: harbor-vs
  namespace: harbor
spec:
  gateways:
  - istio-system/global-gateway
  hosts:
  - <aks-url>
  http:
  # if mTLS mode is STRICT need to set rewrite.authority
  - match:
    - uri:
        prefix: /harbor/v2
    - uri:
        prefix: /harbor/api/
    - uri:
        prefix: /harbor/c/
    - uri:
        prefix: /harbor/chartrepo/
    - uri:
        prefix: /harbor/service/
    rewrite:
      uri: /
    name: core
    route:
    - destination:
        host: harbor-core.harbor.svc.cluster.local
        port:
          number: 80
  - match:
    - uri:
        prefix: /harbor/portal
    rewrite:
      uri: /
    route:
    - destination:
        host: harbor-portal.harbor.svc.cluster.local
        port:
          number: 80