Failed to send an update Symfony 6 Mercure

Question

version: '3.7'
services:
 db:
 image: mariadb:10.2.29
 ports:
 - "3307:3306" #outside:inside docker container from within
 environment:
 - MYSQL_DATABASE=test_db
 - MYSQL_ROOT_PASSWORD=toor
 volumes:
 - persistent:/var/lib/mysql
 - ./docker/build/db/:/docker-entrypoint-initdb.d/
 networks:
 - symfony
 nginx:
 build:
 context: ./docker
 dockerfile: Dockerfile-nginx
 volumes:
 - ./:/var/www/project/:cached
 ports:
 - 8080:80 # Ports that are exposed, you can connect to port 8001 to port 80 of the container.
 links:
 - php
 - mercure
 networks:
 - symfony
 php:
 build:
 context: ./docker
 dockerfile: Dockerfile-php
 expose:
 - 2443
 environment:
 - DATABASE_URL=mysql://root:toor@db/test_db
 volumes:
 - ./:/var/www/project/:cached # Location of the project for php-fpm. Note this should be the same for NGINX.*
 - ./docker/build/php/conf.d/xdebug.ini:/usr/local/etc/php/conf.d/docker-php-ext-xdebug.ini
 - ./docker/build/php/conf.d/error_reporting.ini:/usr/local/etc/php/conf.d/error_reporting.ini
 links:
 - mercure
 networks:
 - symfony
 ###> symfony/mercure-bundle ###
 mercure:
 image: dunglas/mercure
 restart: unless-stopped
 ports:
 - 8081:3000
 environment:
 SERVER_NAME: ':3000'
 MERCURE_PUBLISHER_JWT_KEY: ${MERCURE_JWT_SECRET}
 MERCURE_SUBSCRIBER_JWT_KEY: ${MERCURE_JWT_SECRET}
 # Set the URL of your Symfony project (without trailing slash!) as value of the cors_origins directive
 MERCURE_EXTRA_DIRECTIVES: |-
 cors_origins *
 anonymous
 command: /usr/bin/caddy run --config /etc/caddy/Caddyfile.dev
 volumes:
 - mercure_data:/data
 - mercure_config:/config
 networks:
 - symfony
volumes:
 mercure_data:
 mercure_config:
 persistent:
networks:
 symfony:

config/packages/mercure.yaml

mercure:
 hubs:
 default:
 url: '%env(MERCURE_PUBLIC_URL)%'
 jwt:
 secret: '%env(MERCURE_JWT_SECRET)%'
 publish: [ '*' ]

I have this configuration for my symfony application. The Mercure hub is running fine on localhost:8081. If I send an update over the UI of the hub, my javascript client can receive the update.

The problem is I can not publish an update with HubInterface like this.

$update = new Update('https://example.com/my-private-topic', json_encode($message));
$hub->publish($update);

This said: failed to send an update and nothing more.

I tried to use another JWT according to documentation of symfony 6.3.

// Publisher's JWT must contain this topic, a URI template it matches or * in mercure.publish or you'll get a 401
// Subscriber's JWT must contain this topic, a URI template it matches or * in mercure.subscribe to receive the update

But obvisiously it did not help.

I tried to configure in yaml file like this but nothing happend

framework:
 http_client:
 default_options:
 verify_peer: false

• Fatal Error: Try opening example.com:8081/.well-known/mercure. It should say: Missing "topic" parameter. If it does, that need to be your MERCURE_URL and MERCURE_PUBLILC_URL