Unable to start ruler component

I’m trying spin up loki with helm chart, where I enabled ruler configuration with this

  enabled: true
    type: local
      directory: /rules
  rule_path: /tmp/scratch
  alertmanager_url: http://alertmanager:9093
      store: inmemory
  enable_api: true

However, when I start the loki via helm, the initial logs states this.

level=info ts=2021-07-23T13:07:34.860485766Z caller=main.go:130 msg="Starting Loki" version="(version=2.2.1, branch=HEAD, revision=babea82ef)"
level=info ts=2021-07-23T13:07:34.860742492Z caller=server.go:229 http=[::]:3100 grpc=[::]:9095 msg="server listening on addresses"
level=info ts=2021-07-23T13:07:34.860940278Z caller=modules.go:477 msg="RulerStorage is not configured in single binary mode and will not be started."
level=info ts=2021-07-23T13:07:34.866199695Z caller=shipper_index_client.go:100 msg="starting boltdb shipper in 0 mode"
level=info ts=2021-07-23T13:07:34.866214043Z caller=table_manager.go:171 msg="uploading tables"
level=info ts=2021-07-23T13:07:34.867663072Z caller=modules.go:502 msg="RulerStorage is nil. Not starting the ruler."
level=info ts=2021-07-23T13:07:34.868046541Z caller=module_service.go:59 msg=initialising module=memberlist-kv
level=info ts=2021-07-23T13:07:34.868057538Z caller=module_service.go:59 msg=initialising module=server

I believe the message RulerStorage is nil. Not starting the ruler. is the reason why ruler component couldn’t start?

Is there any way that I can configure the ruler block and start in values.yaml?