Contains an unknown parameter [_routing]

Here is my config file for logstash to connect aws Elasticsearch. It works correctly without "routing"

input {
  file {
    path => "C:/Users/manjur.gani/Desktop/ES/test45.csv"
	start_position=>"beginning"
  }
}
filter {
  csv {
  separator=>","
  columns=>["id","accountId","companyId","click","view","contactId","report"]
  }
  mutate {
	add_field => {"[my_join_field][name]" => "readership"}
	add_field => {"[my_join_field][parent]" => "%{accountId}"}
    add_field => { "actualId" => "%{accountId}%{contactId}"}
}
}

output {
  amazon_es {
    hosts => ["https://search-aws-es-test-umxpgbfghra2gkhz4ltkr6blw4.ap-south-1.es.amazonaws.com"]
	region => "ap-south-1"
	aws_access_key_id=>'XXXXXXXXX'
	aws_secret_access_key=>'XXXXXXXXXXXXXXXXXXXXXX'
	document_id => "%{actualId}"
    index => 'my-index-logstash41'
	routing=>"%{accountId}"
  }
}

ERROR : "body=>"{"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"Action/metadata line [1] contains an unknown parameter [_routing]"}],"type":"p0,"st"

Any solution to this. Thanks