Hi.I'm TheLegendaryVegetable,and i'm glad to be assisiting you today!
If you're talking about game quests and seeing how Bananatic would know you have the app is you download it from the redirected place and make an account on it and send the screenshot to them.Pretty straightforward.Most of the games from quests are Steam Supported so it should redirect you to the steam shop.Search for the app and download it.Keep in mind that some of the games do cost money so you'll have to buy them to do quests.
If this doesn't answer your question then file a support ticket or make your question a bit more specific because I can't really get what your asking and I may have given you a wrong answer.Maybe if the question is more specific I can clarify you with the correct information.
Thanks,have a good time on Bananatic and a good day!
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