Cant Publish Downlink Message Using TTN PAHO & MQTT

I am designing a sensor pushing data via LORA to TTN. I can subscribe to the data streams using Python PAHO. I need to send commands to the sensor. I can do that using the TTN console & the Cayenne dashboard. But I can not figure out what the format for publishing a message using Python PAHO is. I also receive no feedback, acknowledgements, or error messages. I am using MQTT Explorer to try to find the correct message format followingCayenne MQTT API page as a guide. Again, no problem subscribing.
Here is an example of the message I am trying to publish:
TOPIC: v3/testak1@ttn/things/eui-70b3d57ed00XXXX/data/json
All suggestions appreciated.

I’m a little confused. Do you want to use MQTT or LORA?

I want to use both. I am using TTN LoRa. I want to send control commands to the LoRa device. I am using Cayenne to display measurements. I thought I could use Cayenne to relay commands.

It appears I can do that directly through TTN. Maybe that’s my answer. I just use Cayenne to display and use TTN’s MQTT interface to relay commands.

I guess you could use both, but It would be a lot easier and cheaper to just go MQTT if your project supports it.