Smartthings-mqtt-bridge, how do you add a new device with this app?

Grrr, I hate these apps! First new app doesn’t work on my older phone and I’m not adding it to my current phone. So I’ve added it to a weird tablet with a keyboard (a strange device). Once I bring up to main page I see lots of devices including the MQTT device. I’ve added all these devices many years ago. Now I need to change one of the device names but for the life of me I can’t figure out how to get to the add/update the MQTT page for the device. Any pointers?