Kubernetes traefik Ingress - Restrict access to traffic from

Hi everyone, I have a question about ingress and I wish someone here could point me to the right direction. I’m trying to configure ingress for a couple of apps so that only ips within could access the contents. I’m using traefik as my ingress controller and I’m attempting to achieve this by using the traefik.ingress.kubernetes.io/whitelist-source-range annotation, but sadly this approach doesn’t seem to be working. I wonder if NetworkPolicy is the right approach to this, but I’m not sure how. Any help is appreciated~