Web interface not working, can't configure MQTT

I have my Garadget working through the Android app, but I purchased it with the intent to control it via MQTT from Home Assistant.

The instructions for this are to configure MQTT settings via the web interface. The web interface is not responding on my device. I’ve even followed the instructions on how to re-flash the firmware and done so from the GitHub repository… with the same result.

It doesn’t matter if I try with the device reset on its own WiFi network via my phone’s web browser, or if I try when it’s joined to my home network. Multiple machines, multiple browsers, and no web page served up.

Since I can’t seem to find any MQTT configuration settings in the phone app, this is a problem for me.

What am I missing?