Connect to docker-container: Connection reset by peer

Question

I'am trying to connect web- application, deployed from one container, to rabbitmq, deployed at another container.

I created the following docker-compose:

version: '3'

services:
  webapp:
    container_name: chat
    build:
      context: .
    depends_on:
      - broker
    ports:
      - "8080:8080"
    networks:
      - chat_network

  broker:
    container_name: rabbit_chat
    image: rabbitmq
    hostname: broker
    ports:
      - "5672:5672"
      - "15672:15672"
    healthcheck:
        test: ["CMD", "curl", "-f", "http://broker:5672"]
        interval: 30s
        timeout: 10s
        retries: 5
    networks:
      - chat_network

networks:
  chat_network:
    external:
      name: chat_network

webapp is a service of web-application, at which I prescribe following rabbitmq-properties:

host = broker
port = 15672
login = guest
password = guest

And this does not work.

I entered I my containers. Inside rabbit_chat-container I send request (webapp:8080) successfully. But when I send "curl broker:5672 --output - " inside chat-container, I received: "curl: (56) Recv failure: Connection reset by peer".

Inside rabbit_chat-container I run "ncat -v --listen 5672". And receive "Ncat: bind to :::5672: Address already in use. QUITTING."