How to show ads only one time

i have 6 screens in my app , i have placed my ads in screen2 , but while using the app screen2 is opened multiple times and the ads are also shown when screen2 is opened , but i want to show my ads only one time in the entire session of app opened
TEST_ADS.aia (3.3 KB)

Its just an idea, maybe not the best:

Transfer a false in the start Values from Screen1 to every screen you open.
On Screen2 initialize Test if the Value is still false if so, show Ads, then set it on the next screen start value to true.

So if it’s true you showed ads once.