Easy way is click the "do not enable cloud messaging" in the banner. It should be the most straightforward thing you could do.
Open messaging>Settings>Enable cloud messaging to off.
Another way is to execute this command (adb shell or scripter)
pm disable com.miui.cloudservice or use other apps (titanium backup pro) to do this.
Good luck
Lol. I was just assuming qbert456
anyway to both of you, I am logged into "xiaomi services" because you need xiaomi credentials to access themes, so that's why I don't get any notifications.
So if you don't need themes you could also try to disable Xiaomi Services Framework (com.xiaomi.xmsf)