Cannot write to a field alias Error URGENT

[khergner (Korhan Herguner)]

Hi everyone,
I get the following error in logstash but ı don't understand why ı got an error. Can you help me for solution to problem?
Elk & logstash & filebeat version 7.3.0
I use shared to below filebeat template

filebeat.template.json

I send to elk

curl -XPUT -H 'Content-Type: application/json' http://elk:9200/_template/filebeat -d@filebeat.template.json

Logstash output

   output {
	elasticsearch {
	  hosts => localhost
	  manage_template => false
	  index => "%{[@metadata][beat]}-%{[@metadata][version]}-%{+YYYY.MM.dd}"
	}
  }