loki grafana, ingress and namespace

I’ve installed from marketplace Grafana Loki into an existing cluster. I’d want to add /log entry into my ingress in order to point to loki-grafana service.

Here’s an extract of my ingress:

» kubectl get ingress/app -o yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
...
  name: app
  namespace: default
...
spec:
  rules:
  - host: ***.com
    http:
      paths:
      - backend:
          serviceName: api
          servicePort: 80
        path: /api
      - backend:
          serviceName: static
          servicePort: 80
        path: /assets
...
      - backend:
          serviceName: fe
          servicePort: 80
        path: /
      - backend:
          serviceName: loki-grafana
          servicePort: 80
        path: /log
status:
  loadBalancer:
    ingress:
    - ip: ***

but I got an error:

» kubectl describe ingress/app
Name:             app
Namespace:        default
..
Rules:
  Host                     Path  Backends
  ----                     ----  --------
  ***  
                           /api           api:80 (***:3000)
...
                           /log           loki-grafana:80 (<error: endpoints "loki-grafana" not found>)
Annotations:               kubernetes.io/ingress.class: nginx
                           meta.helm.sh/release-name: qme
                           meta.helm.sh/release-namespace: default
                           nginx.ingress.kubernetes.io/ssl-redirect: false
                           nginx.ingress.kubernetes.io/use-regex: true

Maybe the problem is that the loki-grafana service is on another namespace?

» kubectl describe services/loki-grafana -n loki 
Name:              loki-grafana
Namespace:         loki
...