Uniy ads random videos

So I have rewarded videos placed in my game. I would like to add 2 more types.
1) I want a video to play after I collide with a certain object after 5 times (this returns to 0 after it has reached 5 times so it loops everytime)
2) I also want to play an ad to play after I restart a level 7 times (this returns to 0 after it has reached 7 times so it loops everytime)

If anyone has a tutorial or simple lines of code that I can use it would be much appreciated!