Issue with Prometheus using helm charts and Grafana config

I installed prometheus-2.21.0 using helm charts. And trying to configure grafana to use prometheus as datasource.

    - access: proxy
      editable: true
      isDefault: true
        timeInterval: 5s
      name: Prometheus
      orgId: 1
      type: prometheus
      url: <http://prometheus:9090>```

But, I’m getting the following error (from grafana pod log)
`error="http: proxy error: dial tcp: lookup prometheus on no such host`

From grafana dashboard, if change the datasource url to `http://&lt;prometheus_pod_ip&gt;:9090&gt;` its working.

But, whats wrong with the url `<http://prometheus:9090>`  ?