MQTT Explorer not recongizing LilyGo RTL433

I am attempting to set up a LilyGo RTL433 in my home assistant environment. I configured the wifi in the LilyGo to connect to my IoT VLAN. I do see a valid connection in my network controller. I set the MQTT server to my external DuckDNS address and set port 1883 to be forwarded to my raspberry pi in my router.

What do I need to do to see the LIlyGo in the MQTT Explorer?

EDITED:

I set up the LilyGo to be in the same VLAN as the raspberry pi. I set the server to the raspberrt pi ip address. The LilyGo display says that it is connected to wifi but never shows a connection to MQTT.