Setting Traefik as proxy server for a kubernetes service

I am using k3s with traefik. I want to deploy an apache-php k3s service behind traefik. I tried the next:

$ cat deployment.yaml
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: my-php-app
      namespace: kube-system
      labels:
        app: my-php-app
    spec:
      replicas: 1
      selector:
        matchLabels:
          app: my-php-app
      template:
        metadata:
          labels:
            app: my-php-app
        spec:
          containers:
          - name: php-apache
            image: php:8.2-apache # Or your custom image
            ports:
            - containerPort: 80
            volumeMounts:
            - name: php-volume
              mountPath: /var/www/html
          volumes:
          - name: php-volume
            hostPath:
               path: /opt/k3s/storage/www/html    # Path on the host node
               type: DirectoryOrCreate    # Creates the directory if it doesn't exist

---

    apiVersion: v1
    kind: Service
    metadata:
      name: my-php-app-service
      namespace: kube-system
    spec:
      selector:
        app: my-php-app
      ports:
        - protocol: TCP
          port: 80
          targetPort: 80

---

   apiVersion: networking.k8s.io/v1
   kind: Ingress
   metadata:
     name: my-php-app-ingress
     namespace: kube-system

   spec:
     rules:
       - host: myphpsite.cn.lan
         http:
            paths:
               - path: /
                 pathType: Prefix
                 backend:
                    service:
                       name: my-php-app-service
                       port:
                          number: 80


This code “works” i.e. the volume is created at the node that contains the pod. However, independently that I created an index.html file inside the html folder, I get:

curl -k -H "Host: myphpsite.cn.lan" https://192.168.0.215/
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>403 Forbidden</title>
</head><body>
<h1>Forbidden</h1>
<p>You don't have permission to access this resource.</p>
<hr>
<address>Apache/2.4.62 (Debian) Server at myphpsite.cn.lan Port 80</address>
</body></html>

What could be the problem? Are my rules bad?