Session metrics in AppStoreConnect Analytics

In my company, we are keeping a log of the monthly session numbers of our app which is hosted in the AppStore. We have noticed a sharp decline in the numbers over a certain range of numbers and want to find out which users are not returning and cater to their needs to better our app. From where can we get those numbers?

AppStoreConnect does not provide this data. Is there any API for this?

Any help will be much appreciated.

Session metrics in AppStoreConnect Analytics
 
 
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