Thank you very much for the answer.
I have removed “/” and I still cannot see the data.
The W_RST node is the data read from a siemens automata, and I connect it to MQTT OUT to publish the value, with the idea of seeing it in HA-OS as a new sensor.
As a test I have used MQTT IN node to see that they work, and it works fine.
The version of home assistant, Supervisor 2022.07.0
OS 8.4
I have also tried to pass this data to HA with the nodes of (node-red-contrib-home-assistant-websocket) but in HA_OS it asks me (Node-RED Companion Integration) and I have not been able to install it. But that is another story.
Again, many thanks for the help.