Hi @mirou_IoT - I'm trying hard to understand exactly what you have got, but I'm still slightly confused.
- you have a raspberry pi on your local network
- "node-red is in another place" - what do you mean? What is it running on? A different device on a different network? Can your local raspberrypi access the network your other device is running on?
If the machine running node-red is not on the public internet then your raspberry pi is not going to be able to connect to it.
As other people have said, you need an MQTT broker somewhere that both your local device and the machine running node-red can access. This is why it works with
mqtt.eclipse.org - because that is on the public internet.