• Remove comment line (ony remove # symbol) elasticsearch.url: "http://localhost:9200" in kibana.yml file

• Execute this command ./elasticsearch in this folder ELASTICSEARCH_DIR/bin/

• Execute this command ./kibana in this folder KIBANA_DIR/bin/

• Execute this command ./logstash -f logstash.conf in this folder LOGSTASH_DIR/bin/

• You can see logs then your application started on Postman by this link http://localhost:9200/logstash-*/_search

Elastichsearch: http://localhost:9200/

Kibana: http://localhost:5601

Logstash: http://localhost:9600/

Spring Boot App: http://localhost:8080