Getting started with Remote Config (Android)

I've noticed there is an option there of JSON, but what's the difference between this and just using a String that is the JSON ?
Even in code, there is no "getJSON", but instead there is "getString"...

I would like to know how to implement addOnConfigUpdateListener

Does FirebaseRemote config stays "alive" independently of the activity ?

Beta tester od roku 2016 oceňujem,,

Also show how to do it in Flutter as well.

Thanks for sharing.

thank you hard to share information, which is very useful👍