ILM Error while deleting ES index

Hi Team,

I'm facing issue while deleteing index via ILM.

description: i have index with name $webservicelogs* ( where $webservice is name of actual services and after rotation it becomes webservicelogs2022.05.10 similarly for each date.

ILM policy : delete data older than 3 days.
name : webservice-logs-policy

index template:

{
  "index": {
    "lifecycle": {
      "name": "webservice-logs-policy",
      "rollover_alias": "null"
    },
    "number_of_shards": "2",
    "number_of_replicas": "0"
  }
}

Error : illegal_argument_exception: index.lifecycle.rollover_alias [null] does not point to index

Any help would be appreciated.

Hi team

Kindly help, i'm stuck with this.