What is the best frequency for in-app ads?

Question

Android

I thought about inserting an advertisement into the main screen of the game, but I ran into a problem, there are a lot of rather small 480x800 details. If you shrink the game window to insert a banner, everything will be very small, which is not good.
As planned, insert a full-screen banner display in those moments when a player loses a life and display a video during a game over.
Questions:
1) Where else can I insert ads in the application so that there are no violations of the rules (it seems that Google Adsense does not approve of placing banners in the menu, settings, etc.)?
2) How often should banners be shown after losing a life so as not to cause the player to become brutalized?

Answer 1

Frequency 0
Make a separate setting - Allow to show ads @ give bonuses for it
Make a separate button, after pressing which, the user will be shown ads and will be given a bonus

Answer 2

With the loss of life, I would not be annoyed by such an option.
Lives are over.
4:59(8)(7) left to replenish life
[to replenish]
by watching a 30 second video ad.