Congratulations. You are making progress Roman.
Oh, your app has ads? It appears Xiaomi is not comfortable with the way AppyBuilder provides ads. Your software contains what Xiaomi considers illegal item(s), probably because you use the ad provider that is in an AppyBuilder control. We cannot help you with that. App Inventor apps do not have the tools to allow ads. You will probably either have to remove your ads or get assistance
from AppyBuilder to work out the issues with Xiaomi or post your app on Amazon or Google Play.
Rewrite you app in App Inventor and try to publish it in Xiaomi... you can test whether they will accept an AI2 app yourself or you could remove your ad control and publish that way. I expect that your app would publish without the use of the AppyBuilder ad tool... or you might try recoding in Thunkable or another third party AI clone that is designed for building commercial apps.
Good luck.