Network map mqtt topic

Hello, I want to check the network map of my zigbee network. 1 coordinator (cc2531), 1 router (cc2530+cc2591). Therefor I need to subscribe to the topic zigbee2mqtt/bridge/networkmap/graphviz but unfortunately I don’t get this topic. I use mqtt.fx to view the mqtt traffic.
I have the latest version of zigbee2mqtt 1.13.1 installed on an raspberry pi.
Can someone help me with my issue?
Thanks a lot, BR Sebastian

You do need to subscribe to that topic, but for that topic to be created you need to publish
zigbee2mqtt/bridge/networkmap , with payload graphviz

Thank you for the explanation. This worked!