I don't see ads on my game after downloading it from Google play

Hi!
I made my first android game and I tested the game before uploading it to Google Play, and everything was working and ads were showing.
Now after i downloaded the game from Google play to my android device, ads won’t show.
Is it normal for me not to see the ads? (I use admob ads)

BTW check it out and maybe install it on your device, it would mean A LOT!
Thanks!
Download link:
https://play.google.com/store/apps/details?id=com.MICOGames.ImpossibleSummerRun

Do you see ads in it?(at the game over screen) Thanks!

how you solve the problem ???