Rollover ILM policy for existing Index

Elastic Stack Logstash
5 
PUT _ilm/policy/logstash_30days

{
"policy": {
"phases": {
"hot": {
"min_age" : "0ms",
"actions": {
"rollover": {
"max_size":"50gb",
"max_age":"30d"
},
"set_priority": {
"priority": 100
}
}
},
"warm": {

    "actions": {
      
      
      "shrink": {
        "number_of_shards": 1
      },
                
      "set_priority": {
        "priority": 50
      }
    }
  },
  "cold": {
    "min_age": "0d",
    "actions": {
     "freeze": {},
     "set_priority": {
        "priority": 0
      }

    }
  },
  "delete": {
    "min_age": "45d",
    "actions": {
      "delete": {
       "delete_searchable_snapshot" : true

}
}
}
}
}
}

Template:

PUT _template/template_1
{
"index_pattern": ["logstash*"],
"settings":{
"number_of_shards" :1
"number_of_replicas" :1
"name:"logstash_30days"
"rollover_alias" : "logstash_rollover_alias"
}
}

PUT logstash-000001
{
"aliases":{
"logstash_rollover_alias":{
"is_write_index":true
}
}
}

Error:
https://discuss.elastic.co/t/index-lifecycle-rollover-alias-does-not-point-to-index