Xiaomi mihome developer key: how to find in newest App?

Using openHAB 3.4.4 on a Rasbperry Pi on openHABian.

I re-activated my Xiaomi gateway after some time and reset not only my App, but also the gateway. Now it’s connected again, but the newest Android Mi Home App (8.4.702.1310-GooglePlay) has a complete differnet setup. Did anyone find out, how to reach the developer key with the newest App?