How can I implement an 'Unknown Zigbee device' as button

It’s still on the todo list:
https://community.homey.app/t/app-pro-tuya-zigbee-app/26439/1851?u=peter_kawa

(You can discover it, by searching for tz32mtza at that forum topic).

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You get to see the icon, while there’s a bunch of similar models supported:

All this info is available at post #1 of [APP][Pro] Tuya Zigbee App