Yeelight YLXD01YL 320 - German server

I bought 3 Yeelight YLXD01YL 320 Ceiling Light. I added them to Xiaomi Mi app, Yeelight app and Google Home Assistant using China server.
Can I use German server ?
If yes … How ( do I need to reset every lamp, switch to German server then add again all three lamp)?
Xiaomi Mi app still works with lamps? … And what about Google home assistant?

Yes, you can use Germany server of cause.

You need reset the lamps and connect them again.

Say “Ok google, sync my devices” after reconnection.