Hello,
My question is: "what info to enter in MQTT explorer to see into my Wolfram generated MQTT channel".
I have setup a MQTT in Wolfram:
def = CreateChannel["mymqtt", Permissions -> "Public"]
I start the listner:
listner = ChannelListen[def]
I send a value:
ChannelSend[def, "Hello3"]
Then I want to connect using "MQTT explorer" to see into the content 
maybe I need some extra data in the "advanced" section.

This should be simple but I need some directions because I could not make it work. Kind regards, Pieter